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

bool isSubsequence(const string &s, const string &target)
{
    int targetIndex = 0;
    for (char c : s)
    {
        if (c == target[targetIndex])
        {
            targetIndex++;
        }
        if (targetIndex == target.size())
        {
            return true;
        }
    }
    return false;
}

int main()
{
    int T;
    cin >> T;
    string target = "SeriousOJ";

    while (T--)
    {
        int N;
        cin >> N;
        string S;
        cin >> S;

        if (isSubsequence(S, target))
        {
            cout << "YES" << endl;
        }
        else
        {
            cout << "NO" << endl;
        }
    }
    return 0;
}