简简单单

#include<bits/stdc++.h>
using namespace std;
int main(){
	int a;
    cin>>a;
    if(a>=90 && a<=100){
        cout<<"A";
    }else if(a>=80 && a<=89){
        cout<<"B";
    }else if(a>=70 && a<=79){
        cout<<"C";
    }else if(a>=60 && a<=69){
        cout<<"D";
    }else{
        cout<<"E";
    }
	return 0;
}