#include <iostream>
#include <stdlib.h>

using namespace std;

int main()
{
	int number, mark;
	char grade;

	cout << "Number of assignment done=";
	cin >> number;
 	cout << "Examination mark=";
	cin >> mark;

	if (mark >= 30)
	{
		if (number >= 6)
			grade='A';
		else
			grade='B';
	}
	else
	{
		if (number >= 6)
			grade='C';
		else
			grade='F';
	}
  
	cout << "Grade=" << grade << endl;

	system("PAUSE");	
	return 0;
}