小题解

#include<bits/stdc++.h>
using namespace std;
int main(){
    int n;
    cin>>n;
    if(n>=90&&n<=100){
        cout<<'A'<<endl;
    }
    if(n>=80&&n<=89){
        cout<<'B'<<endl;
    }
    if(n>=70&&n<=79){
        cout<<'C'<<endl;
    }
    if(n>=60&&n<=69){
        cout<<'D'<<endl;
    }
    if(n>=0&&n<=59){
        cout<<'E'<<endl;
    }
    return 0;
}