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