using System;

namespace Zad_4
{
    class Program
    {

        static ulong B4(ulong n)
        {

            ulong mask = 7;
            mask <<= 6;
            ulong x = mask & n;

            if (x == 0)
                x = 7;
            else
                x -= 1;

            x <<= 6;
            mask = ~mask;
            n = n & mask;
            n = n | x;

            return x;

        }
        static void Main(string[] args)
        {
            Console.WriteLine(B4(938));
        }
    }
}