4. ASCII Combinations

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;

namespace ForthExam
{
    class Program
    {
        static void Main(string[] args)
        {
            int n = int.Parse(Console.ReadLine());
            int digitSum = 0;
            int smallLettersSum = 0;
            int bigLetterSum = 0;
            int otherSum = 0;
            string digit = null;
            string smallLetters = null;
            string bigLetters = null;
            string otherSymbols = null;
            for (int i = 0; i < n; i++)
            {
                char symbol = char.Parse(Console.ReadLine());

                if (symbol >= '0' && symbol <= '9')
                {
                    digitSum += (int)symbol;
                    digit += symbol;
                }
                else if (symbol >= 'a' && symbol <= 'z')
                {
                    smallLettersSum += (int)symbol;
                    smallLetters += symbol;
                }
                else if (symbol >= 'A' && symbol <= 'Z')
                {
                    bigLetterSum += (int)symbol;
                    bigLetters += symbol;
                }
                else
                {
                    otherSum += (int)symbol;
                    otherSymbols += symbol;
                }

            }
            if (digitSum >= smallLettersSum && digitSum >= bigLetterSum && digitSum >= otherSum)
            {
                Console.WriteLine("Biggest ASCII sum is:{0}", digitSum);
                Console.WriteLine("Combination of characters is:{0}", digit);
            }
            else if (bigLetterSum >= smallLettersSum && bigLetterSum >= otherSum )
            {
                Console.WriteLine("Biggest ASCII sum is:{0}", bigLetterSum);
                Console.WriteLine("Combination of characters is:{0}", bigLetters);
            }
            else if (smallLettersSum >= otherSum)
            {
                Console.WriteLine("Biggest ASCII sum is:{0}", smallLettersSum);
                Console.WriteLine("Combination of characters is:{0}", smallLetters);
            }
            else
            {
                Console.WriteLine("Biggest ASCII sum is:{0}", otherSum);
                Console.WriteLine("Combination of characters is:{0}", otherSymbols);
            }
        }
    }
}