using System;

using System.Collections.Generic;

public class Program

{

    /* Queue via Stacks: Implement a MyQueue class which implements a queue using two stacks. */

    public class QueueViaStacks{

        public Stack<int> FastEnqueueStack; //Enqueue here

        public Stack<int> FastDequeueStack; //Dequeue from here

        public QueueViaStacks(){

            FastEnqueueStack = new Stack<int>();

            FastDequeueStack = new Stack<int>();

        }

        private void Move(Stack<int> source, Stack<int> target){

            while (source.Count != 0){

                target.Push(source.Pop());

            }

        }

        public void Enqueue(int val){

            if (FastEnqueueStack.Count == 0){

                Move(FastDequeueStack, FastEnqueueStack);

            }

            FastEnqueueStack.Push(val);

        }

        public void Dequeue(){

            if (FastDequeueStack.Count == 0){

                Move(FastEnqueueStack, FastDequeueStack);

            }

            FastDequeueStack.Pop();

        }

    }

    public static void Main()

    {

        Console.WriteLine("Hello World");

    }

}