Exam July Morning 2. Letters, Symbols, Numbers

using System;
using System.Collections.Generic;
using System.Globalization;
using System.Linq;
using System.Threading;

public class LettersSymbolsNumbers
{
    private static Dictionary<char, int> alphabet = new Dictionary<char, int>()
    {
        { 'A', 10 }, { 'B', 20 }, { 'C', 30 }, { 'D', 40 }, { 'E', 50 }, { 'F', 60 }, { 'G', 70 },
        { 'H', 80 }, { 'I', 90 }, { 'J', 100 }, { 'K', 110 }, { 'L', 120 }, { 'M', 130 }, { 'N', 140 },
        { 'O', 150 }, { 'P', 160 }, { 'Q', 170 }, { 'R', 180 }, { 'S', 190 }, { 'T', 200 },
        { 'U', 210 }, { 'V', 220 }, { 'W', 230 }, { 'X', 240 }, { 'Y', 250 }, { 'Z', 260 }
    };

    private static char[] whitespaceSymbs = { ' ', '\t', '\r', '\n' };

    public static void Main()
    {
        Thread.CurrentThread.CurrentCulture = CultureInfo.InvariantCulture;
        checked
        {
            int countOfStrings = int.Parse(Console.ReadLine());

            int sumOfLetters = 0;
            int sumOfNums = 0;
            int sumOfSymbols = 0;
            if (countOfStrings > 0)
            {
                for (int i = 0; i < countOfStrings; i++)
                {
                    string inputString = Console.ReadLine().ToUpper();
                    for (int j = 0; j < inputString.Length; j++)
                    {
                        char current = inputString[j];
                        if (alphabet.ContainsKey(current))
                        {
                            sumOfLetters += alphabet[current];
                        }
                        else if (char.IsDigit(current))
                        {
                            int digit = int.Parse(current.ToString());
                            sumOfNums += digit * 20;
                        }
                        else if (!whitespaceSymbs.Contains(current))
                        {
                            sumOfSymbols += 200;
                        }
                    }
                }
            }

            Console.WriteLine("{0}\n{1}\n{2}", sumOfLetters, sumOfNums, sumOfSymbols);
        }
    }
}