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

typedef long long ll;
#define bug(a) cout<<#a<<" : "<<a<<endl;
#define bug2(a,b) cout<<#a<<" : "<<a<<"\t"<<#b<<" : "<<b<<endl;
#define yes cout<<"YES\n";
#define no cout<<"NO\n";

signed main(){
    ios::sync_with_stdio(0);
    cin.tie(0); cout.tie(0);

    int t=1;
    cin>>t;
    int cs=1;
    while(t--){
        string tmp="SeriousOJ";
        int j=0;
        int n;cin>>n;
        string s;cin>>s;
        for(int i=0;i<n;i++){
            if(s[i]==tmp[j])j++;
            if(j==tmp.size())break;
        }
        if(j==tmp.size())yes
        else no
    }
    return 0;
}