#include <bits/stdc++.h>
using namespace std;
#define endl '\n'
#define ll long long
#define bug(a) cout<<#a<<" : "<<a<<endl;
void solve(){
    int n; cin>>n;
    string s; cin>>s;
    string x = "SeriousOJ";
    int i = 0; 
    for(int j = 0; j < n; ++j){
        if(s[j] == x[i]){
            i++;
        }
    }
    if(i==x.size()) cout<<"YES"<<endl;
    else cout<<"NO"<<endl;
}
int main(){
    ios_base::sync_with_stdio(0);
    cin.tie(0);
    
    int t; cin>>t;
    while(t--)
        solve();

    return 0;
}