diff --git a/app/src/main/java/fun/youthlic/Graph.java b/app/src/main/java/fun/youthlic/Graph.java
index aa6d303..6695169 100644
--- a/app/src/main/java/fun/youthlic/Graph.java
+++ b/app/src/main/java/fun/youthlic/Graph.java
@@ -11,6 +11,7 @@ import java.util.Optional;
 import java.util.PriorityQueue;
 import java.util.Random;
 import java.util.function.Function;
+import java.util.stream.IntStream;
 
 public class Graph {
 
@@ -54,6 +55,29 @@ public class Graph {
         }
     }
 
+    public static void main(final String[] args) {
+        final var g = new Graph(
+                "To explore strange new worlds, To seek out new life and new civilizations");
+        final var words = g.findBridgeWords("team", "so");
+        System.out.println(words);
+        final var path = g.findShortestPath("the", "shared");
+        System.out.println(path);
+        System.out.println(
+                g.toDOT(r -> String.format(
+                        "\"%s\" -> \"%s\" [label=\"%d\"%s]",
+                        r.node1 + (path.contains(r.node1) ? "~" : ""),
+                        r.node2 + (path.contains(r.node2) ? "~" : ""),
+                        r.weight,
+                        (path.contains(r.node1) &&
+                                path.contains(r.node2) &&
+                                IntStream.range(0, path.size() - 1).anyMatch(
+                                        i -> path.get(i).equals(r.node1) && path.get(i + 1).equals(r.node2)))
+                                                ? ",color=\"red\""
+                                                : "")));
+        System.out.println(g.computePageRank("new", 0.85));
+        System.out.println(g.randomWalk());
+    }
+
     private final Map<String, Node> nodes;
 
     private Map<Node, Double> pageRanks;
@@ -87,13 +111,13 @@ public class Graph {
         return Optional.of(bridgeWords);
     }
 
-    public Optional<List<String>> findShortestPath(final String word1, final String word2) {
+    public List<String> findShortestPath(final String word1, final String word2) {
         final var startWord = word1.toLowerCase(Locale.ENGLISH);
         final var endWord = word2.toLowerCase(Locale.ENGLISH);
         final var path = new ArrayList<String>();
 
         if (!nodes.containsKey(startWord) || !nodes.containsKey(endWord)) {
-            return Optional.empty();
+            return path;
         }
 
         final Node startNode = nodes.get(startWord);
@@ -101,7 +125,7 @@ public class Graph {
 
         if (startNode == endNode) {
             path.add(startNode.id);
-            return Optional.of(path);
+            return path;
         }
 
         final var distances = new HashMap<Node, Integer>();
@@ -131,7 +155,7 @@ public class Graph {
         }
 
         if (distances.get(endNode) == Integer.MAX_VALUE) {
-            return Optional.of(path);
+            return path;
         }
 
         final var reversePath = new LinkedList<String>();
@@ -141,16 +165,16 @@ public class Graph {
             current = previousNodes.get(current);
         }
 
-        return Optional.of(reversePath);
+        return reversePath;
     }
 
-    public double computePageRank(final String nodeId) {
+    public double computePageRank(final String nodeId, final double d) {
         final Node node = nodes.get(nodeId);
         if (node == null) {
-            return -1.0;
+            return 0.0;
         }
 
-        return pageRanks.getOrDefault(node, -1.0);
+        return pageRanks.getOrDefault(node, 0.0);
     }
 
     public List<String> randomWalk() {
@@ -224,7 +248,7 @@ public class Graph {
         sb.append("digraph G {\n");
         for (final Node node : nodes.values()) {
             for (final String edge : node.getDOTEdges()) {
-                sb.append("    ").append(edge);
+                sb.append("    ").append(edge).append("\n");
             }
         }
         sb.append("}");
diff --git a/app/src/main/java/fun/youthlic/GraphCLI.java b/app/src/main/java/fun/youthlic/GraphCLI.java
index 1c6c245..cc5b3c8 100644
--- a/app/src/main/java/fun/youthlic/GraphCLI.java
+++ b/app/src/main/java/fun/youthlic/GraphCLI.java
@@ -1,20 +1,6 @@
 package fun.youthlic;
 
-import java.io.BufferedReader;
-import java.io.BufferedWriter;
-import java.io.File;
-import java.io.FileReader;
 import java.io.IOException;
-import java.io.InputStreamReader;
-import java.io.OutputStreamWriter;
-import java.nio.charset.StandardCharsets;
-import java.nio.file.Files;
-import java.nio.file.Path;
-import java.nio.file.Paths;
-import java.util.Arrays;
-import java.util.Random;
-import java.util.stream.Collectors;
-import java.util.stream.IntStream;
 
 import org.jline.reader.LineReader;
 import org.jline.reader.LineReaderBuilder;
@@ -23,316 +9,20 @@ import org.jline.terminal.Terminal;
 import org.jline.terminal.TerminalBuilder;
 
 public class GraphCLI {
-    static String readFile(final String filename) {
-        String text = null;
-        try (BufferedReader inputReader = new BufferedReader(new FileReader(new File(filename)))) {
-            text = inputReader.lines().collect(Collectors.joining(System.lineSeparator()));
-        } catch (final IOException e) {
-            System.out.println("Error reading file: " + e.getMessage());
-        }
-        return text;
-    }
 
     public static void main(final String[] args) {
-        GraphCLIHelper helper = null;
-        Terminal terminal = null;
         try {
-            terminal = TerminalBuilder.builder().system(true).build();
+            final Terminal terminal = TerminalBuilder.builder().system(true).build();
+            final LineReader reader = LineReaderBuilder.builder().terminal(terminal).parser(new DefaultParser())
+                    .build();
+            while (true) {
+                final String line = reader.readLine("graph> ");
+                if (line.trim().equalsIgnoreCase("exit"))
+                    break;
+                System.out.println(line);
+            }
         } catch (final IOException e) {
-            e.printStackTrace();
-            System.exit(-1);
-        }
-        final LineReader reader = LineReaderBuilder.builder().terminal(terminal).parser(new DefaultParser())
-                .build();
-        while (true) {
-            final String line = reader.readLine("graph> ");
-            final var commands = line.split("[ \\t]+");
-            if (commands.length == 0) {
-                continue;
-            }
-            switch (commands[0]) {
-                case "load":
-                    if (commands.length != 2) {
-                        System.out.println("Usage: load <filename>");
-                    } else {
-                        final var text = readFile(commands[1]);
-                        if (text == null) {
-                            System.out.println("Load file failed; " + commands[1]);
-                            continue;
-                        }
-                        helper = new GraphCLIHelper(text);
-                    }
-                    break;
-                case "help":
-                    System.out.println("Available commands:");
-                    System.out.println("  show");
-                    System.out.println("  dot");
-                    System.out.println("  help");
-                    System.out.println("  exit");
-                    System.out.println("  random-walk");
-                    System.out.println("  load <filename>");
-                    System.out.println("  page-rank <word>");
-                    System.out.println("  bridge-words <word1> <word2>");
-                    System.out.println("  new-text <text...>");
-                    System.out.println("  shortest-path <word1> <word2>");
-                    break;
-                case "shortest-path":
-                    if (commands.length != 3) {
-                        System.out.println("Usage: shortest-path <word1> <word2>");
-                    } else if (helper == null) {
-                        System.out.println("No graph loaded");
-                        break;
-                    } else {
-                        try {
-                            System.out.println(helper.calcShortestPath(commands[1], commands[2]));
-                        } catch (IOException | InterruptedException e) {
-                            System.out.println(e.getMessage());
-                        }
-                    }
-                    break;
-                case "exit":
-                    return;
-                case "random-walk":
-                    if (commands.length != 1) {
-                        System.out.println("Usage: random-walk");
-                    } else {
-                        if (helper == null) {
-                            System.out.println("No graph loaded");
-                            break;
-                        }
-                        System.out.println(helper.randomWalk());
-                    }
-                    break;
-                case "new-text":
-                    if (commands.length < 2) {
-                        System.out.println("Usage: new-text <text...>");
-                    } else if (helper == null) {
-                        System.out.println("No graph loaded");
-                        break;
-                    } else {
-                        System.out.println(helper.generateNewText(
-                                String.join(" ", Arrays.asList(commands).subList(1, commands.length))));
-                    }
-                    break;
-                case "show":
-                    if (commands.length != 1) {
-                        System.out.println("Usage: show");
-                    } else {
-                        if (helper == null) {
-                            System.out.println("No graph loaded");
-                            break;
-                        }
-                        GraphCLIHelper.showDirectedGraph(helper.graph);
-                    }
-                    break;
-                case "dot":
-                    if (commands.length != 1) {
-                        System.out.println("Usage: dot");
-                    } else {
-                        if (helper == null) {
-                            System.out.println("No graph loaded");
-                            break;
-                        }
-                        System.out.println(helper.graph.toDOT());
-                    }
-                case "page-rank":
-                    if (commands.length != 2) {
-                        System.out.println("Usage: page-rank <word>");
-                    } else if (helper == null) {
-                        System.out.println("No graph loaded");
-                    } else {
-                        final var pageRank = helper.calPageRank(commands[1]);
-                        if (pageRank < 0.0) {
-                            System.out.println("Invalid word");
-                        } else {
-                            System.out.println("PageRank of " + commands[1] + ": " + pageRank);
-                        }
-                    }
-                    break;
-                case "bridge-words":
-                    if (commands.length != 3) {
-                        System.out.println("Usage: bridge-words <word1> <word2>");
-                    } else if (helper == null) {
-                        System.out.println("No graph loaded");
-                    } else {
-                        System.out.println(helper.queryBridgeWords(commands[1], commands[2]));
-                    }
-                    break;
-                default:
-                    System.out.println("Unknown command: " + commands[0]);
-                    break;
-            }
+        } finally {
         }
     }
 }
-
-class GraphCLIHelper {
-    Graph graph;
-
-    GraphCLIHelper(final String text) {
-        graph = new Graph(text);
-    }
-
-    static void showDirectedGraph(final Graph G) {
-        final ProcessBuilder processBuilder = new ProcessBuilder("graph-easy", "--as", "ascii");
-        processBuilder.redirectErrorStream(true);
-        Process process = null;
-        try {
-            process = processBuilder.start();
-        } catch (final IOException e) {
-            System.err.println("Failed to start process");
-            e.printStackTrace();
-        }
-        try (BufferedWriter writer = new BufferedWriter(
-                new OutputStreamWriter(process.getOutputStream(), StandardCharsets.UTF_8))) {
-            writer.write(G.toDOT());
-            writer.flush();
-        } catch (final IOException e) {
-            System.err.println("Failed to write to process");
-            e.printStackTrace();
-        }
-        final StringBuilder output = new StringBuilder();
-        try (BufferedReader reader = new BufferedReader(
-                new InputStreamReader(process.getInputStream(), StandardCharsets.UTF_8))) {
-            String line;
-            while ((line = reader.readLine()) != null) {
-                output.append(line).append(System.lineSeparator());
-            }
-        } catch (final IOException e) {
-            System.err.println("Failed to read from process");
-            e.printStackTrace();
-        }
-        try {
-            final int exitCode = process.waitFor();
-            if (exitCode != 0) {
-                System.err.println("Process exited with code " + exitCode);
-            } else {
-                System.out.println(output.toString());
-            }
-        } catch (final InterruptedException e) {
-            System.err.println("Process interrupted");
-            e.printStackTrace();
-        }
-    }
-
-    String queryBridgeWords(final String word1, final String word2) {
-        final var option = graph.findBridgeWords(word1, word2);
-        if (option.isEmpty()) {
-            return "No " + word1 + " or " + word2 + " in the graph!";
-        }
-        final var bridgeWords = option.get();
-        if (bridgeWords.isEmpty()) {
-            return "No bridge words from " + word1 + " to " + word2 + "!";
-        }
-        final var output = new StringBuilder();
-        output.append("The bridge words from ").append(word1).append(" to ").append(word2).append(" are: ");
-        for (int i = 0; i < bridgeWords.size(); i++) {
-            output.append(bridgeWords.get(i));
-            if (i < bridgeWords.size() - 2) {
-                output.append(", ");
-            } else if (i == bridgeWords.size() - 2) {
-                output.append(", and ");
-            } else {
-                output.append(".");
-            }
-        }
-        return output.toString();
-    }
-
-    String generateNewText(final String inputText) {
-        final var output = new StringBuilder();
-        final var words = inputText.split("\\s+");
-        for (int i = 0; i < words.length; i++) {
-            output.append(words[i]);
-            if (i < words.length - 1) {
-                output.append(" ");
-                final var option = graph.findBridgeWords(words[i], words[i + 1]);
-                if (option.isPresent() && !option.get().isEmpty()) {
-                    final var bridgeWords = option.get();
-                    final Random random = new Random();
-                    final int wordIndex = random.nextInt(bridgeWords.size());
-                    output.append(option.get().get(wordIndex)).append(" ");
-                }
-            }
-        }
-        return output.toString();
-    }
-
-    String calcShortestPath(final String word1, final String word2)
-            throws IOException, InterruptedException {
-        final ProcessBuilder processBuilder = new ProcessBuilder("graph-easy", "--as", "ascii");
-        processBuilder.redirectErrorStream(true);
-        Process process = null;
-        try {
-            process = processBuilder.start();
-        } catch (final IOException e) {
-            throw e;
-        }
-        try (BufferedWriter writer = new BufferedWriter(
-                new OutputStreamWriter(process.getOutputStream(), StandardCharsets.UTF_8))) {
-            writer.write(calcShortestPathToDOT(word1, word2));
-            writer.flush();
-        } catch (final IOException e) {
-            throw e;
-        }
-        final StringBuilder output = new StringBuilder();
-        try (BufferedReader reader = new BufferedReader(
-                new InputStreamReader(process.getInputStream(), StandardCharsets.UTF_8))) {
-            String line;
-            while ((line = reader.readLine()) != null) {
-                output.append(line).append(System.lineSeparator());
-            }
-        } catch (final IOException e) {
-            throw e;
-        }
-        try {
-            final int exitCode = process.waitFor();
-            if (exitCode != 0) {
-                throw new IOException("Process exited with code " + exitCode);
-            } else {
-                return output.toString();
-            }
-        } catch (final InterruptedException e) {
-            throw e;
-        }
-    }
-
-    String calcShortestPathToDOT(final String word1, final String word2) {
-        var option = graph.findShortestPath(word1, word2);
-        if (option.isEmpty()) {
-            return "No " + word1 + " or " + word2 + " in the graph";
-        } else {
-            final var path = option.get();
-            if (path.isEmpty()) {
-                return "No path from " + word1 + " to " + word2;
-            }
-            return graph.toDOT(r -> String.format(
-                    "\"%s\" -> \"%s\" [label=\"%d\"%s]",
-                    r.node1() + (path.contains(r.node1()) ? "~" : ""),
-                    r.node2() + (path.contains(r.node2()) ? "~" : ""),
-                    r.weight(),
-                    (path.contains(r.node1()) && path.contains(r.node2()) &&
-                            IntStream.range(0, path.size() - 1).anyMatch(
-                                    i -> path.get(i).equals(r.node1()) && path.get(i + 1).equals(r.node2())))
-                                            ? ",color=\"red\""
-                                            : ""));
-        }
-    }
-
-    Double calPageRank(final String word) {
-        final var pageRank = graph.computePageRank(word);
-        return pageRank;
-    }
-
-    String randomWalk() {
-        final var text = graph.randomWalk().stream().collect(Collectors.joining(" "));
-        final Path path = Paths.get("output.txt");
-        try {
-            Files.write(path, text.getBytes());
-        } catch (final IOException e) {
-            System.err.println("Failed to write to file");
-            e.printStackTrace();
-        }
-        return text;
-    }
-}
diff --git a/gradle.properties b/gradle.properties
index 6b91bb5..377538c 100644
--- a/gradle.properties
+++ b/gradle.properties
@@ -1,4 +1,5 @@
 # This file was generated by the Gradle 'init' task.
 # https://docs.gradle.org/current/userguide/build_environment.html#sec:gradle_configuration_properties
+
 org.gradle.configuration-cache=true
 
diff --git a/gradlew.bat b/gradlew.bat
index 9d21a21..9b42019 100644
--- a/gradlew.bat
+++ b/gradlew.bat
@@ -1,94 +1,94 @@
-@rem
-@rem Copyright 2015 the original author or authors.
-@rem
-@rem Licensed under the Apache License, Version 2.0 (the "License");
-@rem you may not use this file except in compliance with the License.
-@rem You may obtain a copy of the License at
-@rem
-@rem      https://www.apache.org/licenses/LICENSE-2.0
-@rem
-@rem Unless required by applicable law or agreed to in writing, software
-@rem distributed under the License is distributed on an "AS IS" BASIS,
-@rem WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
-@rem See the License for the specific language governing permissions and
-@rem limitations under the License.
-@rem
-@rem SPDX-License-Identifier: Apache-2.0
-@rem
-
-@if "%DEBUG%"=="" @echo off
-@rem ##########################################################################
-@rem
-@rem  Gradle startup script for Windows
-@rem
-@rem ##########################################################################
-
-@rem Set local scope for the variables with windows NT shell
-if "%OS%"=="Windows_NT" setlocal
-
-set DIRNAME=%~dp0
-if "%DIRNAME%"=="" set DIRNAME=.
-@rem This is normally unused
-set APP_BASE_NAME=%~n0
-set APP_HOME=%DIRNAME%
-
-@rem Resolve any "." and ".." in APP_HOME to make it shorter.
-for %%i in ("%APP_HOME%") do set APP_HOME=%%~fi
-
-@rem Add default JVM options here. You can also use JAVA_OPTS and GRADLE_OPTS to pass JVM options to this script.
-set DEFAULT_JVM_OPTS="-Xmx64m" "-Xms64m"
-
-@rem Find java.exe
-if defined JAVA_HOME goto findJavaFromJavaHome
-
-set JAVA_EXE=java.exe
-%JAVA_EXE% -version >NUL 2>&1
-if %ERRORLEVEL% equ 0 goto execute
-
-echo. 1>&2
-echo ERROR: JAVA_HOME is not set and no 'java' command could be found in your PATH. 1>&2
-echo. 1>&2
-echo Please set the JAVA_HOME variable in your environment to match the 1>&2
-echo location of your Java installation. 1>&2
-
-goto fail
-
-:findJavaFromJavaHome
-set JAVA_HOME=%JAVA_HOME:"=%
-set JAVA_EXE=%JAVA_HOME%/bin/java.exe
-
-if exist "%JAVA_EXE%" goto execute
-
-echo. 1>&2
-echo ERROR: JAVA_HOME is set to an invalid directory: %JAVA_HOME% 1>&2
-echo. 1>&2
-echo Please set the JAVA_HOME variable in your environment to match the 1>&2
-echo location of your Java installation. 1>&2
-
-goto fail
-
-:execute
-@rem Setup the command line
-
-set CLASSPATH=%APP_HOME%\gradle\wrapper\gradle-wrapper.jar
-
-
-@rem Execute Gradle
-"%JAVA_EXE%" %DEFAULT_JVM_OPTS% %JAVA_OPTS% %GRADLE_OPTS% "-Dorg.gradle.appname=%APP_BASE_NAME%" -classpath "%CLASSPATH%" org.gradle.wrapper.GradleWrapperMain %*
-
-:end
-@rem End local scope for the variables with windows NT shell
-if %ERRORLEVEL% equ 0 goto mainEnd
-
-:fail
-rem Set variable GRADLE_EXIT_CONSOLE if you need the _script_ return code instead of
-rem the _cmd.exe /c_ return code!
-set EXIT_CODE=%ERRORLEVEL%
-if %EXIT_CODE% equ 0 set EXIT_CODE=1
-if not ""=="%GRADLE_EXIT_CONSOLE%" exit %EXIT_CODE%
-exit /b %EXIT_CODE%
-
-:mainEnd
-if "%OS%"=="Windows_NT" endlocal
-
-:omega
+@rem
+@rem Copyright 2015 the original author or authors.
+@rem
+@rem Licensed under the Apache License, Version 2.0 (the "License");
+@rem you may not use this file except in compliance with the License.
+@rem You may obtain a copy of the License at
+@rem
+@rem      https://www.apache.org/licenses/LICENSE-2.0
+@rem
+@rem Unless required by applicable law or agreed to in writing, software
+@rem distributed under the License is distributed on an "AS IS" BASIS,
+@rem WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+@rem See the License for the specific language governing permissions and
+@rem limitations under the License.
+@rem
+@rem SPDX-License-Identifier: Apache-2.0
+@rem
+
+@if "%DEBUG%"=="" @echo off
+@rem ##########################################################################
+@rem
+@rem  Gradle startup script for Windows
+@rem
+@rem ##########################################################################
+
+@rem Set local scope for the variables with windows NT shell
+if "%OS%"=="Windows_NT" setlocal
+
+set DIRNAME=%~dp0
+if "%DIRNAME%"=="" set DIRNAME=.
+@rem This is normally unused
+set APP_BASE_NAME=%~n0
+set APP_HOME=%DIRNAME%
+
+@rem Resolve any "." and ".." in APP_HOME to make it shorter.
+for %%i in ("%APP_HOME%") do set APP_HOME=%%~fi
+
+@rem Add default JVM options here. You can also use JAVA_OPTS and GRADLE_OPTS to pass JVM options to this script.
+set DEFAULT_JVM_OPTS="-Xmx64m" "-Xms64m"
+
+@rem Find java.exe
+if defined JAVA_HOME goto findJavaFromJavaHome
+
+set JAVA_EXE=java.exe
+%JAVA_EXE% -version >NUL 2>&1
+if %ERRORLEVEL% equ 0 goto execute
+
+echo. 1>&2
+echo ERROR: JAVA_HOME is not set and no 'java' command could be found in your PATH. 1>&2
+echo. 1>&2
+echo Please set the JAVA_HOME variable in your environment to match the 1>&2
+echo location of your Java installation. 1>&2
+
+goto fail
+
+:findJavaFromJavaHome
+set JAVA_HOME=%JAVA_HOME:"=%
+set JAVA_EXE=%JAVA_HOME%/bin/java.exe
+
+if exist "%JAVA_EXE%" goto execute
+
+echo. 1>&2
+echo ERROR: JAVA_HOME is set to an invalid directory: %JAVA_HOME% 1>&2
+echo. 1>&2
+echo Please set the JAVA_HOME variable in your environment to match the 1>&2
+echo location of your Java installation. 1>&2
+
+goto fail
+
+:execute
+@rem Setup the command line
+
+set CLASSPATH=%APP_HOME%\gradle\wrapper\gradle-wrapper.jar
+
+
+@rem Execute Gradle
+"%JAVA_EXE%" %DEFAULT_JVM_OPTS% %JAVA_OPTS% %GRADLE_OPTS% "-Dorg.gradle.appname=%APP_BASE_NAME%" -classpath "%CLASSPATH%" org.gradle.wrapper.GradleWrapperMain %*
+
+:end
+@rem End local scope for the variables with windows NT shell
+if %ERRORLEVEL% equ 0 goto mainEnd
+
+:fail
+rem Set variable GRADLE_EXIT_CONSOLE if you need the _script_ return code instead of
+rem the _cmd.exe /c_ return code!
+set EXIT_CODE=%ERRORLEVEL%
+if %EXIT_CODE% equ 0 set EXIT_CODE=1
+if not ""=="%GRADLE_EXIT_CONSOLE%" exit %EXIT_CODE%
+exit /b %EXIT_CODE%
+
+:mainEnd
+if "%OS%"=="Windows_NT" endlocal
+
+:omega
diff --git a/output.txt b/output.txt
deleted file mode 100644
index dc0e3ea..0000000
--- a/output.txt
+++ /dev/null
@@ -1,2 +0,0 @@
-B1 output.txt
-scientist carefully analyzed it again
diff --git a/settings.gradle.kts b/settings.gradle.kts
index ffdc88e..156979d 100644
--- a/settings.gradle.kts
+++ b/settings.gradle.kts
@@ -4,6 +4,7 @@
  * The settings file is used to specify which projects to include in your build.
  * For more detailed information on multi-project builds, please refer to https://docs.gradle.org/8.13/userguide/multi_project_builds.html in the Gradle documentation.
  */
+
 plugins {
     // Apply the foojay-resolver plugin to allow automatic download of JDKs
     id("org.gradle.toolchains.foojay-resolver-convention") version "0.9.0"
diff --git a/test.txt b/test.txt
deleted file mode 100644
index 97d4c04..0000000
--- a/test.txt
+++ /dev/null
@@ -1,2 +0,0 @@
-B1 test.txt
-The scientist carefully analyzed the data, wrote a detailed report, and shared the report with the team, but the team requested more data, so the scientist analyzed it again.