#include <bits/stdc++.h>
using namespace std;
#define ll long long
#define nl "\n"
#define yes << "YES\n"
#define no << "NO\n"
#define sp " "
void solve()
{
    int n;
    cin >> n;
    string s = "SeriousOJ", p;
    cin >> p;
    int a = 0;
    for (int i = 0; i < s.size(); i++)
    {
        int val = 0;
        for (int j = a; j < n; j++)
        {
            if (s[i] == p[j])
            {
                   val = 1;
                a = j + 1;
                break;
             
            }
        }
        if (val == 0)
        {
            cout no;
            return;
        }
    }
    cout yes;
}

int main()
{
    ios_base::sync_with_stdio(false);
    cin.tie(NULL);
    ll t;
    cin >> t;
    for (ll i = 0; i < t; i++)
        solve();
    return 0;
}