Rage_Quit

using System;
using System.Collections.Generic;
using System.Text;
using System.Text.RegularExpressions;

namespace Rage_Quit_v3._0
{
    class Program
    {
        static void Main(string[] args)
        {
            Regex pattern = new Regex(@"(\D+)(\d+)");
            string input = Console.ReadLine().ToUpper();
            var result = new List<string>();
            var charsUsed = new List<char>();
            int counter = 0;
            foreach (Match item in pattern.Matches(input))
            {
                int count = int.Parse(item.Groups[2].Value);
                string word = item.Groups[1].Value;
                for (int i = 0; i < count; i++) result.Add(word);
                foreach (char Char in item.Groups[1].Value)
                {
                    if (!charsUsed.Contains(Char))
                    {
                        charsUsed.Add(Char);
                        counter++;
                    }
                }
            }
            Console.WriteLine($"Unique symbols used: {counter}");
            Console.WriteLine(string.Join("", result));
        }
    }
}