#include <bits/stdc++.h>
using namespace std;
typedef long long int ll;

void solve() {
  ll n, j = 0, k = 0; cin >> n;
  string s, dum = "SeriousOJ"; cin >> s;
  for ( j = 0; j < dum.size(); j++) {
    ll ok = 0;
    for (ll i = k; i < n; i++) {
      if (s[i] == dum[j]) {
        k = i + 1;
        ok = 1;
        break;
      }
    }
    if (ok == 0)break;
  }
  cout << (j == dum.size() ? "YES" : "NO") << endl;
}

int main() {
  ios::sync_with_stdio(false);
  cin.tie(NULL);
  int tt = 1;
  cin >> tt;
  while (tt--) {
    solve();
  }
  return 0;
}