#include <bits/stdc++.h>
#define nl '\n'
#define ll long long int
#define all(v) v.begin(),v.end()
#define print(v) for(auto data : v) cout << data << " "; cout << nl
using namespace std;
void solve()
{
    int n; string s; cin >> n >> s;
    string tmp = "SeriousOJ";
    deque<char> dq;
    for(auto data : tmp) dq.push_back(data);
    for(auto data : s) 
    {
        if(dq.empty()) break;
        if(dq.front() == data) dq.pop_front();
    }
    cout << ((dq.empty())? "YES" : "NO") << nl << nl;
}
int main()
{
    ios_base::sync_with_stdio(false); cin.tie(NULL);

    int t; cin >> t; 
    while (t--) solve();

    return 0;
}