EmojiDetector -ExamPreparation

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

namespace EmojiDetector
{
    class Program
    {
        static void Main(string[] args)
        {
            string input = Console.ReadLine();
            var listCoolEmojies = new List<string>();
            Regex regexForThreshold = new Regex(@"[0-9]");
            MatchCollection matchesForThreshold = regexForThreshold.Matches(input);
            BigInteger threshold = 1;
            foreach (Match match in matchesForThreshold)
            {
                string matchString= (match.Value);
                int number = int.Parse(matchString);
                threshold = threshold * number;
            }

            Regex regexForEmojies = new Regex(@"(::|\*\*)(?<emoji>[A-Z][a-z]{2,})\1");
            MatchCollection matchesValidEmojies = regexForEmojies.Matches(input);
            foreach (Match match in matchesValidEmojies )
            {
                string validEmoji = match.Value;
                string validEmojiOnlyLetter = match.Groups["emoji"].Value;
                int sumASCII = 0;
                for (int i = 0; i < validEmojiOnlyLetter.Length; i++)
                {
                    sumASCII += validEmojiOnlyLetter[i];
                }

                if(sumASCII > threshold)
                {
                    listCoolEmojies.Add(validEmoji);
                }
            }

            Console.WriteLine($"Cool threshold: {threshold}");
            Console.WriteLine($"{matchesValidEmojies.Count} emojis found in the text. The cool ones are: ");
            Console.WriteLine(string.Join(Environment.NewLine,listCoolEmojies));
        }
    }
}