#include <stdio.h>
#include <string.h>

#define TARGET "SeriousOJ"

int main() {
    int T;
    scanf("%d", &T);

    while (T--) {
        int N;
        scanf("%d", &N);
        char S[N+1];
        scanf("%s", S);

        int i = 0, j = 0;
        while (S[i] != '\0' && TARGET[j] != '\0') {
            if (S[i] == TARGET[j]) {
                j++;
            }
            i++;
        }

        if (TARGET[j] == '\0') {
            printf("YES\n");
        } else {
            printf("NO\n");
        }
    }

    return 0;
}