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import java.util.ArrayList;
import java.util.List;

// Node class to represent each
// page in the browser history
class Node {
    // Stores the URL of the page
    String data;
    // Pointer to the next page in history
    Node next;
    // Pointer to the previous page in history
    Node back;

    // Default constructor
    Node() {
        data = "0";
        next = null;
        back = null;
    }

    // Constructor with data
    Node(String x) {
        data = x;
        next = null;
        back = null;
    }

    // Constructor with data and pointers
    Node(String x, Node next, Node random) {
        data = x;
        this.next = next;
        back = random;
    }
}

// Browser class to manage
// the browsing functionality
class Browser {
    // Pointer to the current
    // page being viewed
    Node currentPage;

    // Constructor to initialize
    // the browser with a homepage
    Browser(String homepage) {
        currentPage = new Node(homepage);
    }

    // Visit a new page and
    // update the browsing history
    void visit(String url) {
        Node newNode = new Node(url);
        // Set the back pointer of the
        // new page to the current page
        newNode.back = currentPage;
        // Set the next pointer of the
        // current page to the new page
        currentPage.next = newNode;
        // Update the current page to the new page
        currentPage = newNode;
    }

    // Go back a certain number
    // of steps in history
    String back(int steps) {
        // While there are steps
        // and a previous page exists
        while (steps > 0 && currentPage.back != null) {
            // Move to the previous page
            currentPage = currentPage.back;
            // Decrement the steps count
            steps--;
        }
        // Return the URL of the current page
        return currentPage.data;
    }

    // Go forward a certain number of steps in history
    String forward(int steps) {
        // While there are steps and a next page exists
        while (steps > 0 && currentPage.next != null) {
            // Move to the next page
            currentPage = currentPage.next;
            // Decrement the steps count
            steps--;
        }
        // Return the URL of the current page
        return currentPage.data;
    }
}

public class Main {
    public static void main(String[] args) {
        // Create a browser with a homepage
        Browser browser = new Browser("homepage.com");
        List<List<String>> queries = new ArrayList<>();
        // Visit 'google.com'
        queries.add(List.of("visit", "google.com")); 
        // Visit 'bing.com'
        queries.add(List.of("visit", "bing.com")); 
        // Go back one step
        queries.add(List.of("back", "1")); 
        // Go forward one step
        queries.add(List.of("forward", "1")); 

        System.out.println("Queries:");
        // Loop through each query and execute it
        for (List<String> query : queries) {
            if (query.get(0).equals("visit")) {
                System.out.println("Visited " + query.get(1));

                // Execute visit query
                browser.visit(query.get(1));
            } else if (query.get(0).equals("back")) {
                System.out.print("Back " + query.get(1) + " steps" + ": ");

                // Execute back query and print the result
                System.out.println(browser.back(Integer.parseInt(query.get(1))));