#include<iostream> using namespace std; int main(){ int score; cin>>score; if(score>=90){ cout<<'A'<<endl;; }else if(score>=80){ cout<<'B'<<endl; }else if(score>=70){ cout<<'C'<<endl; }else if(score>=60){ cout<<'D'<<endl; }else{ cout<<'E'<<endl; } return 0; }