#include<iostream>
#include<string>
using namespace std;

int main(){
    int t;cin>>t;
    string found="SeriousOJ";
    while(t--){
        int n;
        string s;cin>>n>>s;
        int j=0;
        for(int i=0;i<n;i++){
            if(s[i] == found[j])
            {
                j++;
            }
            if(j==found.size()){
                break;
            }
        }
        if(j==found.size()){
            cout<< "YES"<<endl;
        }
        else{
            cout<<"NO"<<endl;
        }
    }
    return 0;

}