Queue using stacks

class MyQueue {
public:
    stack <int> s1; //Primary Stack
    stack <int> s2; //Secondary Stack

    MyQueue() {

    }

    void push(int x) {
        s1.push(x);
    }

    int pop() {
       while(s1.size()!=0){
           s2.push(s1.top());
           s1.pop();
       }
       int ans = s2.top();
        s2.pop();

       while(s2.size()!=0){
           s1.push(s2.top());
           s2.pop();
       }

        return ans;

    }

    int peek() {
        while(s1.size()!=0){
           s2.push(s1.top());
           s1.pop();
       }
       int ans = s2.top();

       while(s2.size()!=0){
           s1.push(s2.top());
           s2.pop();
       }

        return ans;
    }

    bool empty() {

        if(s1.size()==0){
            return true;
        }

        return false;


    }
};