#include <iostream>
using namespace std;

int main() {

    int score;
    cin >> score;

    // write your code here......
    if (score < 0 | score > 100) {
        cout << "成绩不合法";
    } else {
        switch (score / 10) {
            case 6:
                cout << "及格" ;
                break;
            case 7:
                cout << "中" ;
                break;
            case 8:
                cout << "良" ;
                break;
            case 9:
                cout << "优秀" ;
                break;
            case 10:
                cout << "优秀" ;
                break;
            default:
                cout << "差" ;

        }




    }


    return 0;
}