package main

import "fmt"

// Queue structure
type Queue struct {
    items []int
}

// Enqueue operation
func (q *Queue) Enqueue(item int) {
    q.items = append(q.items, item)
}

// Dequeue operation
func (q *Queue) Dequeue() (int, error) {
    if len(q.items) == 0 {
        return 0, fmt.Errorf("queue is empty")
    }
    item := q.items[0]
    q.items = q.items[1:]
    return item, nil
}

// Front operation
func (q *Queue) Front() (int, error) {
    if len(q.items) == 0 {
        return 0, fmt.Errorf("queue is empty")
    }
    return q.items[0], nil
}

// IsEmpty operation
func (q *Queue) IsEmpty() bool {
    return len(q.items) == 0
}

func main() {
    queue := &Queue{}
    
    // Enqueue elements
    queue.Enqueue(1)
    queue.Enqueue(2)
    queue.Enqueue(3)
    
    // Dequeue and print elements
    fmt.Println("Queue operations:")
    for !queue.IsEmpty() {
        item, _ := queue.Dequeue()
        fmt.Printf("%d ", item)
    }
}

public class Queue {
    private int maxSize;
    private int[] queueArray;
    private int front;
    private int rear;
    private int currentSize;
    
    // Constructor
    public Queue(int size) {
        maxSize = size;
        queueArray = new int[maxSize];
        front = 0;
        rear = -1;
        currentSize = 0;
    }
    
    // Enqueue operation
    public void enqueue(int value) {
        if (currentSize < maxSize) {
            if (rear == maxSize - 1) {
                rear = -1;
            }
            queueArray[++rear] = value;
            currentSize++;
        } else {
            System.out.println("Queue is full");
        }
    }
    
    // Dequeue operation
    public int dequeue() {
        if (currentSize > 0) {
            int temp = queueArray[front++];
            if (front == maxSize) {
                front = 0;
            }
            currentSize--;
            return temp;
        } else {
            System.out.println("Queue is empty");
            return -1;
        }
    }
    
    // Front operation
    public int front() {
        return queueArray[front];
    }
    
    // IsEmpty operation
    public boolean isEmpty() {
        return (currentSize == 0);
    }
    
    public static void main(String[] args) {
        Queue queue = new Queue(3);
        
        // Enqueue elements
        queue.enqueue(1);
        queue.enqueue(2);
        queue.enqueue(3);
        
        // Dequeue and print elements
        System.out.println("Queue operations:");
        while (!queue.isEmpty()) {
            System.out.print(queue.dequeue() + " ");
        }
    }
}

from collections import deque

class Queue:
    def __init__(self):
        self.items = deque()
    
    def enqueue(self, item):
        self.items.append(item)
    
    def dequeue(self):
        if not self.is_empty():
            return self.items.popleft()
        return None
    
    def front(self):
        if not self.is_empty():
            return self.items[0]
        return None
    
    def is_empty(self):
        return len(self.items) == 0
    
    def size(self):
        return len(self.items)

# Example usage
if __name__ == "__main__":
    queue = Queue()
    
    # Enqueue elements
    queue.enqueue(1)
    queue.enqueue(2)
    queue.enqueue(3)
    
    # Dequeue and print elements
    print("Queue operations:")
    while not queue.is_empty():
        print(queue.dequeue(), end=" ")