#include<bits/stdc++.h>
using namespace std;
#define ll long long int 
int main()
{
    ll tc;
    cin>>tc;
    while(tc--)
    {
        ll n;
        cin>>n;
        string s;
        cin>>s;
        string k;
        k="SeriousOJ";
        ll c=0;
        for(int i=0;i<s.size();i++)
        {
            if(c<k.size() && s[i]==k[c])
                c++;
        }
        if(c==k.size())
            cout<<"YES\n";
        else
            cout<<"NO\n";

    }
}