using System;

using System.Collections;

public class Program

{

    public static void Main()

    {

     Queue q = new Queue();  

    q.enQueue(1);  

    q.enQueue(2);  

    q.enQueue(3);  

    Console.Write(q.deQueue()+" ");  

    Console.Write(q.deQueue()+" ");  

    Console.Write(q.deQueue());  

    }

    public class Queue{

        Stack s1 = new Stack();

        Stack s2 = new Stack();

        public void enQueue(int x)

        {

            while(s1.Count>0)

            {

                s2.Push(s1.Pop());

            }

            s1.Push(x);

            while(s2.Count>0)

            {

                s1.Push(s2.Pop());

            }

        }

        public int deQueue(){

            if(s1.Count==0){

                Console.WriteLine("Q is Empty"); 

            }

            // Return top of s1  

        int x = (int)s1.Peek();  

        s1.Pop();  

        return x;  

        }

    }

}