Emodji Detector

using System;
using System.Collections.Generic;

namespace Emoji_Detector
{
    class Program
    {
        static void Main(string[] args)
        {
            string line = Console.ReadLine();
            int coolThreshold = 1;
            string currentEmodji = "";
            int coolness = 0; ;
            List<string> validEmojis = new List<string>();
            List<string> coolEmodjis = new List<string>();
            for (int i = 0; i < line.Length; i++)
            {
                if (Char.IsDigit(line[i]))
                {
                    coolThreshold *= int.Parse(line[i].ToString());

                }
            }
            Console.WriteLine($"Cool threshold: {coolThreshold}");
            for (int i = 0; i < line.Length - 1; i++)
            {
                if ((line[i] == '*') || (line[i] == ':'))
                {
                    if (line[i] == '*')
                    {
                        if (line[i + 1] == '*')
                        {
                            for (int j = i + 2; j < line.Length - 1; j++)
                            {
                                if (line[j] == '*')
                                {
                                    if (line[j + 1] == '*')
                                    {
                                        currentEmodji = line.Substring(i, j + 2 - i);
                                        if ((currentEmodji[2] >= 65) && (currentEmodji[2] <= 90))
                                        {
                                            validEmojis.Add(currentEmodji);
                                            i = j + 2;
                                            break;
                                        }
                                        else
                                        {
                                            i = j + 2;
                                            break;
                                        }
                                    }
                                }
                            }
                        }
                    }
                    if (line[i] == ':')
                    {
                        if (line[i + 1] == ':')
                        {
                            for (int j = i + 2; j < line.Length - 1; j++)
                            {
                                if (line[j] == ':')
                                {
                                    if (line[j + 1] == ':')
                                    {
                                        currentEmodji = line.Substring(i, j + 2 - i);
                                        if ((currentEmodji[2] >= 65) && (currentEmodji[2] <= 90))
                                        {
                                            validEmojis.Add(currentEmodji);
                                            i = j + 2;
                                            break;
                                        }
                                        else
                                        {
                                            i = j + 2;
                                        }
                                    }

                                }
                            }
                        }
                    }
                }
            }
            Console.WriteLine($"{validEmojis.Count} emojis found in the text. The cool ones are:");
            foreach (string Emodji in validEmojis)
            {
                for (int i = 2; i < Emodji.Length - 2; i++)
                {
                    if (Char.IsLetter(Emodji[i]))
                    {
                        coolness += Emodji[i];
                    }
                }
                if (coolness >= coolThreshold)
                {
                    coolEmodjis.Add(Emodji);

                }
                coolness = 0;
            }
            foreach (var coolEmodji in coolEmodjis)
            {
                Console.WriteLine(coolEmodji);
            }
        }
    }
}