Help me in solving DSAJ18A problem

My issue

Why it is showing error

My code

import java.util.LinkedList;
import java.util.Queue;

class QueueExample {
    public static void main(String[] args) {
        // Create a new queue of integers using a LinkedList implementation
        Queue<Integer> queue = new LinkedList<>();

        // Enqueue elements (adding elements to the queue)
        queue.offer(5);  // Add the integer 5 to the end of the queue
        queue.offer(10); // Add the integer 10 to the end of the queue
        queue.offer(15); // Add the integer 15 to the end of the queue

        // Dequeue elements (removing elements from the front of the queue)
        int frontElement = queue.poll(); // Remove and retrieve the front element (5)
        System.out.println("Front Element: " + frontElement); // Print the removed element

        // Peek at the front element (view the front element without removing it)
        int peekedElement = queue.peek(); // View the front element (10)
        System.out.println("Front Element (Peeked): " + peekedElement); // Print the viewed element

        // Check if the queue is empty
        boolean isEmpty = queue.isEmpty(); // Check if the queue has no elements
        System.out.println("Is Queue Empty? " + isEmpty); // Print whether the queue is empty or not

Learning course: DSA using Java
Problem Link: CodeChef: Practical coding for everyone