9498번:시험성적

import java.util.Scanner;

public class Main {

       public static void main(String[] args) {
   		Scanner sc = new Scanner(System.in);
   		int a;
   		
   		a = sc.nextInt();
   		   		
        if(a<=100&&a>=90)
        {
        	System.out.println("A");
        }
        else if(a<=89&&a>=80)
        {
        	System.out.println("B");
        }
        else if(a<=79&&a>=70)
        {
        	System.out.println("C");
        }
        else if(a<=69&&a>=60)
        {
        	System.out.println("D");
        }
        else
        {
        	System.out.println("F");
        }
        

          		
     }
}

https://www.acmicpc.net/problem/9498