Exam Score (if-else)

import java.util.Scanner;

public class Main {

    public static void main(String[] args) {

        int score;

        Scanner keyboard = new Scanner(System.in);

        System.out.println("Enter your exam score");
        score = keyboard.nextInt();

        if (score < 60) {
            System.out.println("Your grade is F");
        }
        else {
            if (score < 70) {
                System.out.println("Your grade is D");
            }
            else {
                if (score < 80) {
                    System.out.println("Your grade is C");
                }
                else {
                    if (score <90) {
                        System.out.println("Your grade is B");
                    }
                    else {
                        if (score >= 90) {
                            System.out.println("Your grade is A");
                        }
                    }
                }
            }
        }
    }
}