#include<iostream>
#include<string>
using namespace std ;
class M {
    public :
    string n,s;
    int m;
    char g ;
    M(string nn , string ss , int mm,char gg){
        n = nn;
        s = ss;
        m = mm;
        g = gg;
    }
   
    void mrk(){
        if (m < 0){
            cout<<"Invalid input";
        }
        else{
            if (m >= 90 && m<100){
                g = "A" ;
            }
            else if (m < 90 && m >= 75){
                g = "B" ;
            }
            else if (m < 75 && m >= 50){
                g = "C" ;
            }
            else if (m < 50){
               g = "F" ;
        }
    }
    cout<<"Name: "<<n<<endl;
    cout<<"subject: "<<s<<endl;
    cout<<"Marks: "<<m<<endl;
    cout<<"Grade: "<<g<<endl;
    }
    
    
};
int main(){
    string n , s ;
    char g ;
    int m ;
    getline(cin , n);
    getline(cin , s);
    if(!n.empty() && n.back() == '\r')n.pop_back();
    if(!s.empty() && s.back() == '\r')s.pop_back();
    cin>>m;
    cin>>g;
    M obj(n,s,m ,g);
    
    obj.mrk();
    
}