Magic Car Numbers

using System;

class MagicCarNumbers
{

    static void Main()
    {
        int totalNumValue = int.Parse(Console.ReadLine());
        string[] letters = new string[] { "A", "B", "C", "E", "H", "K", "M", "P", "T", "X" };
        int counter = 0;
        int cA = 40;
        for (int digitOne = 0; digitOne <= 9; digitOne++)
        {
            for (int digitTwo = 0; digitTwo <= 9; digitTwo++)
            {
                for (int firstLetter = 0; firstLetter < letters.Length; firstLetter++)
                {
                    for (int secondLetter = 0; secondLetter < letters.Length; secondLetter++)
                    {
                        if (((cA + digitOne * 4 + ConvertLetter(letters[firstLetter])
                                 + ConvertLetter(letters[secondLetter])) == totalNumValue) && (digitOne == digitTwo))
                        {
                            counter++;
                        }
                        if (((cA + digitOne * 3 + digitTwo + ConvertLetter(letters[firstLetter])
                                 + ConvertLetter(letters[secondLetter])) == totalNumValue) && (digitOne != digitTwo))
                        {
                            counter++;
                        }
                        if (((cA + digitOne * 2 + digitTwo * 2 + ConvertLetter(letters[firstLetter])
                                 + ConvertLetter(letters[secondLetter])) == totalNumValue) && (digitOne != digitTwo))
                        {
                            counter += 3;
                        }
                        if (((cA + digitOne + digitTwo * 3 + ConvertLetter(letters[firstLetter])
                                 + ConvertLetter(letters[secondLetter])) == totalNumValue) && (digitOne != digitTwo))
                        {
                            counter++;
                        }
                    }
                }
            }
        }
        Console.WriteLine(counter);
    }

    private static int ConvertLetter(string letterToInt)
    {
        int numberToReturn = 0;
        switch (letterToInt)
        {
            case "A": numberToReturn = 10; break;
            case "B": numberToReturn = 20; break;
            case "C": numberToReturn = 30; break;
            case "E": numberToReturn = 50; break;
            case "H": numberToReturn = 80; break;
            case "K": numberToReturn = 110; break;
            case "M": numberToReturn = 130; break;
            case "P": numberToReturn = 160; break;
            case "T": numberToReturn = 200; break;
            case "X": numberToReturn = 240; break;

        }
        return numberToReturn;
    }

}