#include <iostream> #include <cstdio> #include <cmath> using namespace std; int main(){ int x; cin>>x; if (x>=90){ cout<<"A"; }else if(80<=x && x<=90){ cout<<"B"; }else if(70<=x && 80>=x){ cout<<"c"; }else if(60<=x && 70>=x){ cout<<"D"; }else{ cout<<"E"; } }