BitFlipper

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;


class Program
{
    static void Main()
    {
        UInt64 number =  UInt64.Parse(Console.ReadLine());


        for (int i = 63; i >= 2; i--)
        {
            if (GetBit(number, i) == 0 && GetBit(number, i - 1) == 0 && GetBit (number, i - 2) == 0)
            {

               number = SetBit(number, i, 1);
               number = SetBit(number, i - 1, 1);
               number = SetBit(number, i - 2, 1);
                i -= 2;
                continue;
            }
            else if (GetBit(number, i) == 1 && GetBit(number, i - 1) == 1 && GetBit (number, i - 2) == 1)
            {
               number =  SetBit(number, i, 0);
               number =  SetBit(number, i - 1, 0);
               number = SetBit(number, i - 2, 0);
                i -= 2;
            }
        }

        Console.WriteLine(number);

    }

    static UInt64 GetBit(UInt64 number, int position)
    {
        UInt64 bit = (number >> position) & 1;
        return bit;
    }

    static UInt64 SetBit(UInt64 number, int position, int bit)
    {
        UInt64 mask = (UInt64)1 << position;
        if (bit == 1)
        {
            number = number | mask;
        }
        else
        {
            number = number & (~mask);
        }


        return number;
    }

    //static int ExchangeBits(int number, int position1, int position2)
    //{
    //    int bit1 = GetBit(number, position1);
    //    int bit2 = GetBit(number, position2);
    //    number = SetBit(number, bit1, position2);
    //    number = SetBit(number, bit2, position1);


    //    return number;
    //}
}