import java.util.*;      // needed for Scanner class
public class IfElseIf {
   public static void main(String[] args) {
	   double score;
		Scanner inputScanner = new Scanner(System.in);
	   System.out.println("Please enter your test score: ");
		score = inputScanner.nextInt();
		if (score >= 90) {
		   System.out.println("A");
		}
		else if (score >= 80 && score < 90) {
		   System.out.println("B");
		}
		else if (score >= 70 && score < 80) {
		   System.out.println("C");
		}
		else if (score >= 60 && score < 70) {
		   System.out.println("D");
		}
		else if (score < 60) {
		   System.out.println("F");
		}
		System.out.println("the end");
	}
}