#include <iostream>
using namespace std;

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

    // 判断成绩等级,是否合法
    if(score <= 100 && score >=90)
        cout << "优秀";
    if(score <= 89 && score >= 80)
        cout << "良";
    if(score <= 79 && score >= 70)
        cout << "中";
    if(score <= 69 && score >= 60)
        cout << "及格";
    if(score <= 59 && score >= 0)
        cout << "差";
    if(score < 0 || score > 100) 
        cout << "成绩不合法";

    return 0;
}