#include <iostream>
#include <queue>
using namespace std;

int main() {
    queue<int> Q;
    int a = 5;
    Q.push(1);
    Q.push(2);
    Q.push(3);
    Q.push(a);

    cout << Q.size() << endl;

    Q.pop();
    cout << Q.size() << endl;
    Q.pop();
    cout << Q.size() << endl;
    return 0;
}