#include <iostream>
using namespace std;

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

    // write your code here......
    if (score > 100 || score < 0) {
        cout << "成绩不合法" << endl;
    } else if (score >= 90 && score <= 100) {
        cout << "优秀" << endl;
    } else if (score >= 80 && score <= 89) {
        cout << "良" << endl;
    } else if (score >= 70 && score <= 79) {
        cout << "中" << endl;
    } else if (score >= 60 && score <= 69) {
        cout << "及格" << endl;
    } else if (score >= 0 && score <= 59) {
        cout << "差" << endl;
    }
    

    return 0;
}