//on the name of Allah:)
#include<bits/stdc++.h>
#define int         long long
#define Endl        "\n"
#define pi          2 * acos(0.0)
#define mod         1000000007
#define Mul(a,b)    (a%mod * b%mod)%mod
#define Add(a,b)    (a%mod + b%mod)%mod
#define all(x)      (x).begin(),(x).end()
#define allr(x)     (x).rbegin(),(x).rend()
#define gcd(x, y)   (__gcd(x, y))
#define lcm(x, y)   ((x/gcd(x, y))*y)
#define faster      cin.tie(NULL), cout.tie(NULL);
#define TC          int t ; cin>>t ; for(int i=1;i<=t;i++)
const int N = 1e6 + 7;
using namespace std;

bool isSubsequence(string str1, string str2) {
    int n1 = str1.size();
    int n2 = str2.size();

    int j = 0;


    for (int i = 0; i < n2 && j < n1; ++i) {
        if (str1[j] == str2[i]) {
            ++j; // Move pointer of str1
        }
    }


    return j == n1;
}

void s()
{
  int n;
  cin>>n;
  string s;
  cin>>s;

  if(isSubsequence("SeriousOJ",s))cout<<"YES"<<endl;
  else cout<<"NO"<<Endl;

}



int32_t main()
{
    ios::sync_with_stdio(false);
    //faster
    TC
    {
        //cout<<"Case "<<i<<": ";
        s();

    }



}