RageQuit90/100

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

class RageQuit
{
    static void Main()
    {
        var input = Console.ReadLine().ToUpper();
        var nonDigits = new StringBuilder();//new List<char>();
        var sb = new StringBuilder();
        //var strings = new List<char>();
        var uniques = Regex.Replace(input, @"[\d]+", "");
        for (int i = 0; i < input.Length; i++)
        {
            if (!char.IsDigit(input[i]))
            {
                nonDigits.Append(input[i]);//nonDigits.Add(input[i])
            }
            else if (char.IsDigit(input[i]))
            {
                var digit = int.Parse(char.GetNumericValue(input[i]).ToString());
                if (i + 1 < input.Length && digit > 0)
                {
                    if (char.IsDigit(input[i + 1]))
                    {
                        var digitTens = char.GetNumericValue(input[i]).ToString();
                        var digitOnes = char.GetNumericValue(input[i + 1]).ToString();
                        var number = int.Parse(digitTens) * 10 + int.Parse(digitOnes);
                        for (int d = 0; d < number; d++)
                        {
                            //strings.AddRange(nonDigits);
                            sb.Append(nonDigits);
                        }
                        i = i + 1;
                    }
                    else if (!char.IsDigit(input[i + 1]))
                    {
                        for (int d = 0; d < digit; d++)
                        {
                            //strings.AddRange(nonDigits);
                            sb.Append(nonDigits);
                        }
                    }
                }
                else if (i + 1 == input.Length)
                {
                    for (int d = 0; d < digit; d++)
                    {
                        //strings.AddRange(nonDigits);
                        sb.Append(nonDigits);
                    }
                }
                nonDigits.Clear();
            }
        }
        var count = uniques.ToString().Distinct().ToArray();
        Console.WriteLine("Unique symbols used: {0}", new string(count).Length);
        //Console.WriteLine(string.Join("",strings));
        Console.WriteLine(sb);
    }
}