#include<iostream> using namespace std; int main(){ int CR7; cin>>CR7; if(CR7>=90){ cout<<"A"; } else if(80<=CR7&&CR7<90){ cout<<"B"; }else if(70<=CR7&&CR7<80){ cout<<"C"; }else if(60<=CR7&&CR7<70){ cout<<"D"; } else{ cout<<"E"; } return 0; }