import java.util.Scanner;

public class BranchLoopExample
{
    public static void main(String [] args)
    {
	Scanner in = new Scanner(System.in);
	float percent = -1;
	boolean quit = false;
	String answer;

	do
	{
	    System.out.print("Term % score: ");
	    percent = in.nextFloat();
	    if ((percent >= 0) && (percent <= 49))
		System.out.println("F");
	    else if ((percent >= 50) && (percent <= 59))
		System.out.println("D");
	    else if ((percent >= 60) && (percent <= 69))
		System.out.println("C");
	    else if ((percent >= 70) && (percent <= 79))
		System.out.println("B");
	    else if ((percent >= 80) && (percent <= 100))
		System.out.println("A");
	    else
		System.out.println("Error");
	    System.out.print("Quit program ('y' = yes): ");
	    in.nextLine();   // Remove newline after user input
	    answer = in.nextLine();
	    if (answer.length() > 0)   // If user types in no data and hits enter by mistake
	    {
		if ((answer.charAt(0) == 'y') || (answer.charAt(0) == 'Y'))
		    quit = true;
	    }
	} while(quit == false);
    }
}