#include <bits/stdc++.h>

using namespace std;
const int N = 1e5 + 10;
int q[N], hh, tt;
int main() {
    int n;
    cin >> n;
    while (n--) {
        string op;
        cin >> op;
        if (op == "push") {
            cin >> q[++tt];
            if (tt == N) tt = 0; // 加冒了，就回到0
        } else if (op == "empty")
            hh == tt ? cout << "YES" << endl : cout << "NO" << endl;
        else if (op == "query")
            printf("%d\n", q[hh]);
        else {
            hh++;
            if (hh == N) hh = 0; // 加冒了，就回到0
        }
    }
    return 0;
}