class MyStack { public: MyStack() {

}
queue<int> line1;
queue<int> line2;

void push(int x) {
    line2.push(x);

    while (!line1.empty()) {
        int temp = line1.front();
        line1.pop();
        line2.push(temp);
    }
    while (!line2.empty()) {
        int temp = line2.front();
        line2.pop();
        line1.push(temp);
    }
}

int pop() {
    int info = line1.front();
    line1.pop();
    return info;
}

int top() {
    return line1.front();
}

bool empty() {
    if(line1.empty()) {
        return true;
    }
    else {
        return false;
    }
}

};