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


#include<ext/pb_ds/assoc_container.hpp>
#include<ext/pb_ds/tree_policy.hpp>
using namespace __gnu_pbds;

template<typename T> using o_set = tree<T, null_type, std::less<T>, 
rb_tree_tag, tree_order_statistics_node_update>;


void solve() {
    int n;
    cin >> n;
    string s, t = "SeriousOJ";
    cin >> s;
    int ind = 0, m = (int) t.size();
    for (int i = 0; i < n; i++) {
        if(ind == m) break;
        if(s[i] == t[ind]) ind++;
    }
    if(ind == m) cout << "YES\n";
    else cout << "NO\n";
    
}

signed main() {
    ios_base::sync_with_stdio(false);
    cin.tie(NULL);

    int t = 1; 
    cin>>t;
    for(int tc = 1; tc <= t; tc++) {
        // cout<<"Case "<<tc<<":";
        solve();
    }
}