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

#define ll long long
#define endl '\n'
#define pi 2*acos(0.0)



void solve() 
{

    int n; cin >> n;
    string s; cin >> s;
    string p = "SeriousOJ";
    int pt = 0;

    for (int i = 0; i < n; i++) {
        if (s[i] == p[pt]) {
            pt++;
        }
    }

    cout << (pt == 9 ? "YES\n" : "NO\n"); 


}

int main () 
{

    ios::sync_with_stdio(false); cin.tie(nullptr);
    

    ll t = 1; 
    cin >> t;
    while(t--) {
        solve();
    }

    return 0;


}