#include <bits/stdc++.h>
using namespace std;

#define int long long

signed main()
{

    /*
    stack<int> s;
    int x;
    s.size();
    s.empty();
    s.push(x);
    s.top();
    s.pop();
    */
    /*
    queue<int> q;
    int x;
    q.size();
    q.empty();
    q.push(x);
    q.front();
    q.pop();
    */
    /*
    deque<int> q;
    int x;
    q.size();
    q.empty();
    q.front();
    q.push_front(x);
    q.pop_front();

    q.back();
    q.push_back(x);
    q.pop_back();
    */
    /*
    priority_queue<int> q;
    int x;
    q.size();
    q.empty();
    q.push(x);
    q.top(); // max element
    q.pop() // delete max element
    */
}