/// Abdur Rahman Salman ///

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

#define endl "\n"
#define trace(x) cout << #x << ": " << x << endl
int32_t main()
{
    ios_base::sync_with_stdio(0);
    cin.tie(0); cout.tie(0);
    int t; cin >> t;
    while(t--)
    {
        int n; cin >> n;
        string s; cin >> s;
        string t = "SeriousOJ";
        int j = 0;
        // trace(s);
        // trace(t);
        for(int i = 0; i < n; )
        {
            if(s[i] == t[j])
            {
                //cout << s[i];
                i++; 
                j++;
            }
            else i++;
        }
        cout << ((j == t.size()) ? "YES" : "NO") << endl; 
    }
    return 0;
}