GenomeDecoder80

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

namespace GenomeDecoder
{
    class GenomeDecoder
    {
        static void Main(string[] args)
        {
            string[] input = Console.ReadLine().Split(new char[]{' '},StringSplitOptions.RemoveEmptyEntries);
            int n = int.Parse(input[0]);
            int m = int.Parse(input[1]);
            string genome = Console.ReadLine();
            StringBuilder result = new StringBuilder();
            string pattern = @"(?<number>[0-9]*)(?<letter>[A-Z]{1})";
            Match match = Regex.Match(genome, pattern);
            while (match.Success)
            {
                int number = 1; // initially one sequence of every letter
                if (char.IsDigit(match.ToString()[0])) // if match begins with digit, then we matched the group "number" and parse it
                {
                    number = int.Parse(match.Groups["number"].ToString());
                }
                char[] ch = match.Groups["letter"].ToString().ToCharArray();
                result.Append(new string(ch[0],number));
                match = match.NextMatch();
            }
            int numberOfRows = result.Length / n; // if we have reminder then add 1 (e.g. 9.77 means 10 rows)
            if (result.Length%n!=0)
            {
                numberOfRows++;
            }

            //find padding
            int padding = 0;
            string num = numberOfRows.ToString();
            for (int k = 0; k < num.Length; k++)
            {
                padding++;
            }
            int i = 1;
            while(result.Length!=0)
            {
                string line = GetLineReady(result,n,m);
                Console.Write(i.ToString().PadLeft(padding));
                Console.Write(' ');
                Console.WriteLine(line);
                i++;
            }
        }

        private static string GetLineReady(StringBuilder result, int n, int m)
        {
            StringBuilder line = new StringBuilder(result.Length);
            for (int i = 0; i < n; i++)
            {
                if (i>=result.Length)
                {
                    result.Clear();
                    return line.ToString();
                }
                if (i!=0 && i%m == 0)
                {
                    line.Append(' ');
                }
                line.Append(result[i]);
                if (i==n-1)
                {
                    line = new StringBuilder(line.ToString().TrimStart().TrimEnd());
                }
            }
            result.Remove(0, n);
            return line.ToString();
        }
    }
}