using System;
using System.Text.RegularExpressions;

class Program
{
    static void Main()
    {
        string str = "Hello world 😀🙏☀⛿"; // 1F600 GRINNING FACE, 1F64F PERSON WITH FOLDED HANDS, 2600 BLACK SUN WITH RAYS, 26FF WHITE FLAG WITH HORIZONTAL MIDDLE BLACK STRIPE
        Regex regexEmoji = new Regex(@"\uD83D[\uDE00-\uDEFF]|[\u2600-\u26FF]");
        MatchCollection matches = regexEmoji.Matches(str);
        int count = matches.Count;
        Console.WriteLine(count);
    }
}