[백준] 9498번 : 시험 성적 - C#

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

using System;

class Program
{
    static void Main() {
        string s=Console.ReadLine();
        int n=int.Parse(s);
        if(n>=90) Console.Write("A");
        else if(n>=80) Console.Write("B");
        else if(n>=70) Console.Write("C");
        else if(n>=60) Console.Write("D");
        else Console.Write("F");
    }
}