BOJ9498]시험 성적

import java.util.Scanner;
public class BOJ9498 {
    public static void main(String[] args) {
        try(Scanner sc = new Scanner(System.in)) {
            int Score=sc.nextInt();
            
            if(Score>89) System.out.println("A");
            else if(Score>79) System.out.println("B");
            else if(Score>69) System.out.println("C");
            else if(Score>59) System.out.println("D");
            else System.out.println("F");
        }
    }
}