queue<int> queue_int;
queue<string> queue_string;
#include <iostream>
#include <queue>
using namespace std;
int main() {
queue<int> que;
que.push(1);
que.push(2);
cout << que.front() << endl;
que.push(3);
que.pop();
cout << que.front() << endl;
cout << que.front() << endl;
que.pop();
cout << que.front() << endl;
return 0;
}