using System;
public class Program
{
public static void Main()
int score = 80;
Console.Write("Input score :");
score = int.Parse(Console.ReadLine());
if(score>=80){
Console.WriteLine("Grade : A");
}
else if(score >=70 && score<80){
Console.WriteLine("Grade : B");
if(score<60){
Console.WriteLine("Grade : F");
//Console.WriteLine("A");
//Console.WriteLine("F");
