public class Program

{

    public static void Main()

    {

        var i = 6;

        var c = BitCount(i);

        System.Console.WriteLine(c);

    }

    // Method found here: https://stackoverflow.com/a/62264795/2228526

    public static int BitCount(int n)

    {

        var count = 0;

        while (n != 0)

        {

            count++;

            n &= (n - 1); //walking through all the bits which are set to one

        }

​

        return count;

    }

}