C# 백준 5622번 문제 다이얼

using System;

namespace ConsoleApp3
{
    class Program
    {
        static void Main(string[] args)
        {
            int sum = 0;
            char[] ch = Console.ReadLine().ToUpper().ToCharArray();

            for (int i = 0; i<ch.Length; i++)
            {
                if ('A' <= ch[i] && ch[i] <= 'C')
                {
                    sum += 3; 
                }
                else if ('D' <= ch[i] && ch[i] <= 'F')
                {
                    sum += 4;
                }
                else if ('G' <= ch[i] && ch[i] <= 'I')
                {
                    sum += 5;
                }
                else if ('J' <= ch[i] && ch[i] <= 'L')
                {
                    sum += 6;
                }
                else if ('M' <= ch[i] && ch[i] <= 'O')
                {
                    sum += 7;
                }
                else if ('P' <= ch[i] && ch[i] <= 'S')
                {
                    sum += 8;
                }
                else if ('T' <= ch[i] && ch[i] <= 'V')
                {
                    sum += 9;
                }
                else if ('W' <= ch[i] && ch[i] <= 'Z')
                {
                    sum += 10;
                }
            }
            Console.WriteLine(sum);
        }      
    }
}