#include <iostream>
using namespace std;

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

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