//
// use a method to do summation 1+2+...+n
//

import java.util.Scanner;
class PassOrFail
{
	public static void main(String[] args)
	{
		Scanner input = new Scanner(System.in);

		while(input.hasNextDouble())
		{
			double score = input.nextDouble();
			String grade = PorF(score);
			System.out.println(score + ", its letter is: " + grade);
		}
		System.out.println("\n\n");
	}

	//--------------------------
	public static String PorF(double score)
	{
		if(score>60.)
			return "P";
		else
			return "F";
	}
}