#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;
}