#include<bits/stdc++.h> using namespace std; int main(){ int score; cin>>score; if (score>90){ cout<<"A"; } else if (score>=80 && score<=89){ cout<<"B"; } else if (score>=70 && score<=79){ cout<<"C"; } else if (score>=60 && score<=69){ cout<<"D"; } else{ cout<<"E"; } return 0; }