#include <bits/stdc++.h>
using namespace std;

int32_t main() {
    ios::sync_with_stdio(false);
    cin.tie(0); 
    cout.tie(0);

    #ifdef SUBLIME
        freopen("inputf.in", "r", stdin);
        freopen("outputf.out", "w", stdout);
        freopen("error.txt", "w", stderr);
    #endif

    int tt;
    cin >> tt;
    while (tt--) {
        int n;
        string s;
        cin >> n >> s;

        string t = "SeriousOJ";
        int i = 0, j = 0;
        while (i < n && j < (int)t.size()) {
            if (s[i] == t[j]) {
                i++;
                j++;
            }
            else i++;
        }

        if (j == (int)t.size()) cout << "YES\n";
        else cout << "NO\n";
    }
    return 0;
}