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

#define nl '\n'
#define ll long long
#define int long long
#define pii pair<int, int> 



void solve(){
    int n; cin >> n;
    string s, t = "SeriousOJ"; cin >> s;
    int m = t.size();
    int i=0, j = 0;
    while(i<n and j<m) {
        if(s[i] == t[j]) j++;
        ++i;
    }
    cout << (j==m?"YES\n" : "NO\n");
}

int32_t main(){
    ios_base::sync_with_stdio(0);
    cin.tie(0);

    int t = 1, tc = 0;
    cin >> t ;
    while(t--){
        // cout << "Case " << ++tc  << ": ";
        solve();
    }
    return 0;
}