// editor3
#include<iostream>
#include<string>
using namespace std;
class Student{
    private:
    string name;
    string subject;
    int marks;
    public:
    Student(string n,string s,int m)
    {
        name=n;
        subject=s;
        marks=m
    }
    void display()
    {
        if(name.empty() || subject.empty() || marks>100)
        {
            cout<<"Invalid input";
            return ;
        }
        char grade;
        if(marks>=90) grade = 'A';
        else if(marks>=75) grade = 'B';
        else if(marks>=50) grade = 'C';
        cout<<"Name:"<<name<<endl;
        cout<<"Subject:"<<subject<<endl;
        cout<<"Marks:"<<marks<<endl;
        cout<<"Grade:"<<grade<<endl;
        
    }
};
int main()
{
    string name,subject;
    int marks;
    getline(cin,name);
    getline(cin,subject);
    cin>>marks;
    Student s(name,subject,marks);
    s.display();
    return 0;
}