#include<bits/stdc++.h>
using namespace std;
#define yes cout<<"YES"<<"\n";
#define no cout<<"NO"<<"\n";
#define forn  for(int i=0;i<n;i++);
#define acin  for(int i=0;i<n;i++)cin>>arr[i];
#define v vector<int>arr(n);
//#define int long long 
void solve()
{
  int n;
  cin>>n;
 string s;
 cin>>s;
 string s1="SeriousOJ";
 int cnt=0;
 for (int i = 0, j = 0; i < n; i++)
 {
     if (s[i] == s1[j])
     {
         j++;
         cnt++;
     }
 }
 if (s1.size() == cnt)cout<<"YES"<<endl;
     
 else cout<<"NO"<<endl;
}
int main()
{
    int t;
    cin>>t;
    while (t--)
    { 
         solve();
    }
    
 

}