import java.util.Stack; //史上最菜代码 public class Solution { Stack stack1 = new Stack(); Stack stack2 = new Stack();

public void push(int node) {
    stack1.push(node);
}

public int pop() {
    int num = 0;
	while(!stack1.empty()) {
		stack2.push(stack1.pop());
	}
	
	if(!stack2.empty()) {
		num = stack2.pop();
		while(!stack2.empty()) {
    		stack1.push(stack2.pop());
    	}
	}
	return num;
}

}