#include #include #include

using namespace std; queue arr; int m; signed main() { cin >> m; while(m--) { string s; int x; cin >> s; if(s == "push") { cin >> x; arr.push(x); } else if(s == "pop") { if(arr.empty()) { continue; } else { arr.pop(); } } else if(s == "empty") { if(arr.empty()) { cout << "YES" << endl; } else { cout << "NO" << endl; } } else if(s == "query") { if(arr.empty()) { cout << "empty" << endl; } else { cout << arr.front() << endl; } } } return 0; }