tj

#include <bits/stdc++.h>
using namespace std;
int main(){
	int a,b,c;
    cin>>a>>b>>c;
    if(a>=90){
		cout<<"A";    	   
    }else if(a>=80&&a<90){
        cout<<"B";
    }else if(a>=70&&a<80){
        cout<<"C";
    }else if(a>=60&&a<70){
        cout<<"D";
    }else{
        cout<<"E";
    }
    return 0;
}