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