package javaqueue2;
import java.util.*;

public class JavaQueue2{
static class Stack {
	static Queue<Integer> q1 = new LinkedList<Integer>();
	static Queue<Integer> q2 = new LinkedList<Integer>();
	static int curr_size;
	Stack() 
        {
	    curr_size = 0;  
        }

	static void push(int x)
	{	curr_size++;
		// Push x first in empty q2
		q2.add(x);

		// Push all the remaining elements in q1 to q2.
		while (!q1.isEmpty()) {
			q2.add(q1.peek());
			q1.remove();	}

		// swap the names of two queues
		Queue<Integer> q = q1;
		q1 = q2;
		q2 = q;   }
        
        static int pop() {
            if (q1.isEmpty())
	        return -1;
            else{
            curr_size--;  
                return q1.remove();
            }}

        static int top() {
            if (q1.isEmpty())
	         return -1;
            return q1.peek();  }

        static int size()
        {   return curr_size;  }      
}

public static void main(String[] args)
{   Stack s = new Stack();
    s.push(1); 
    s.push(2); 
    s.push(3);

    System.out.println("current size: " + s.size());
    System.out.println(s.top());
    System.out.println("-----------------------------");
    System.out.println(s.pop());
    System.out.println(s.pop());
    System.out.println("current size: " + s.size());
    System.out.println(s.top());
	
}       
}