Hexidecimal Input To Decimal

using System;

class HexToDecimal
{
    static void Main()
    {
        string hex = Console.ReadLine();
        long result = 0;
        int bufferNum = 0;
        bool check = false;

        for (int cnt = 1; cnt <= hex.Length; cnt++)
        {
            result *= 16;
            check = int.TryParse(hex[cnt - 1].ToString(), out bufferNum);
            if(!check)
            {
                bufferNum = getDecimal(hex[cnt-1]);
            }
            result += bufferNum;
        }
        Console.WriteLine(result);
    }

    private static int getDecimal(char p)
    {
        int value = 0;
        switch (p)
        {
            case 'A':
                value = 10;
                break;
            case 'B':
                value = 11;
                break;
            case 'C':
                value = 12;
                break;
            case 'D':
                value = 13;
                break;
            case 'E':
                value = 14;
                break;
            case 'F':
                value = 15;
                break;
        }
        return value;
    }
}