#include <bits/stdc++.h>
using namespace std;
#define ll long long
#define debug(a) cout << #a << "-->" << (a) << '\n';

int main()
{
    ios ::sync_with_stdio(false);
    cin.tie(NULL);
    int t;
    cin>>t;
    while(t--)
    {
        int n;
        cin>>n;
        string s;
        cin>>s;
        string ans="SeriousOJ";
        int h=0;
        int u=ans.size();
        if(n<u)
        {
            cout<<"NO\n";
            
        }
        else
        {
        string aa;
        for(int i=0;i<u;i++)
        {
            while(h<n)
            {
                if(ans[i]==s[h])
                {
                    aa.push_back(s[h]);
                    h++;
                    break;
                }
                else{
                    h++;
                }
            }
        }
        (aa==ans)?cout<<"YES\n":cout<<"NO\n";
        }
    }
    return 0;
}