1 #include<iostream>
 2 using namespace std;
 3 int main()
 4 {
 5     int n;
 6     while(cin>>n)
 7     {
 8         if(n>=90&&n<=100)cout<<"A"<<endl;
 9         else if(n>=80&&n<=89)cout<<"B"<<endl;
10         else if(n>=70&&n<=79)cout<<"C"<<endl;
11         else if(n>=60&&n<=69)cout<<"D"<<endl;
12         else if(n>=0&&n<=59)cout<<"E"<<endl;
13         else cout<<"Score is error!"<<endl;
14     }
15     return 0;
16 }