import java.util.*;

public class MyStack {

Queue<Integer> q;

public MyStack() {

q = new ArrayDeque();

}

// Push element x onto stack.

public void push(int x) {

q.offer(x);

}

// Removes the element on top of the stack.

public void pop() {

int n = q.size();

if (n == 0) return;

for (int i = 0; i < n - 1; ++i) {

int t = q.poll();

q.offer(t);

}

q.poll();

}

// Get the top element.

public int top() {

int n = q.size();

for (int i = 0; i < n - 1; ++i) {

int t = q.poll();

q.offer(t);

}

int result = q.poll();

q.offer(result);

return result;

}

// Return whether the stack is empty.

public boolean empty() {

return q.isEmpty();

}

}