<p>using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading;
using System.Threading.Tasks;
using System.IO;
using System.Xml;
using System.Text.RegularExpressions;

public interface IMathUtilities
{
  int HammingWeight(int value);
}

public class Solution : IMathUtilities
{
  public int HammingWeight(int value)
  {
     value = value - ((value &gt;&gt; 1) &amp; 0x55555555);
     value = (value &amp; 0x33333333) + ((value &gt;&gt; 2) &amp; 0x33333333);
     return (((value + (value &gt;&gt; 4)) &amp; 0x0F0F0F0F) * 0x01010101) &gt;&gt; 24;
  }
}
</p>