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

int main() {
    string target = "SeriousOJ";
    int n, t;
    cin >> t;

    while (t--) {
        cin >> n;
        string S;
        cin >> S;

        int index = 0;
        int len = target.length();
        bool found = false;

        for (char ch : S) {
            if (ch == target[index]) {
                index++;
            }
            if (index == len) {
                found = true;
                break;
            }
        }

        if (found) {
            cout << "YES" << endl;
        } else {
            cout << "NO" << endl;
        }
    }

    return 0;
}