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