#include <iostream>
using namespace std;

int main() {
    
    int score;
    cin >> score;

    if(score >= 90 && score <=100)
    cout <<"优秀"<<endl;
    else if(score >= 80 && score < 90)
    cout <<"良"<<endl;
    else if(score >= 70 && score < 80)
    cout <<"中"<<endl;
    else if(score >= 60 && score <70)
    cout <<"及格"<<endl;
    else if(score >=0 && score < 60)
     cout <<"差"<<endl;
     else
      cout <<"成绩不合法"<<endl;
    

    return 0;
}