Bit exchange

using System;
using System.Linq;

namespace Operators
{
    class Program
    {

        static void Main(string[] args)
        {

            int number = int.Parse(Console.ReadLine());
            for (int i =3;i<6;i++)
            {
                int mask = 1 << i;
                int wantedBit = (number & mask) >> i;

                int mask2 = 1 << i + 21;
                int otherBit = (number & mask2) >> i + 21;

                
                if (wantedBit==1)
                {
                     mask = 1 << i + 21;
                     number = number | mask; 
                }
               else if (wantedBit == 0)
                {
                    mask = ~(1 << i + 21);
                     number = number & mask;
                }
                if (otherBit == 1)
                {
                    mask = 1 << i ;
                     number = number | mask;
                }
               else if (otherBit == 0)
                {
                    mask = ~(1 << i );
                     number = number & mask;
                }

            }
            Console.WriteLine(number);
        }
    }

}