#include <bits/stdc++.h>
using namespace std;
#define ll long long 
#define nl '\n'
#define f(i,s,n) for(int i = s; i < n; i++)
// #define int long long

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

signed main() {
   ios_base::sync_with_stdio(false);cin.tie(NULL);cout.tie(NULL);
   int T = 1;
   cin>>T;
   for(int tc = 1; tc <= T; tc++){
        solve();
   }
}