MyQueue

public class MyQueue<T> {
	Stack<T> s1, s2;
	
	public MyQueue(){
		s1 = new Stack<T>();
		s2 = new Stack<T>();
	}
	
	public void add(T val){
		s1.push(val);
	}
	
	public int size(){
		return s1.size() + s2.size();
	}
	
	public void shiftStacks(){
		if(s2.isEmpty()){
			while(!s1.isEmpty()){
				s2.push(s1.pop());
			}
		}
	}
	
	public T remove(){
		shiftStacks();
		return s2.pop();
	}
	
	public T peek(){
		shiftStacks();
		return s2.peek();
	}
}