Problem 15

/* Problem 15
 * Write a program that exchanges bits 3, 4 and 5
 * with bits 24, 25 and 26 of given 32-bit unsigned integer.
*/

using System;

class BitsExchange
{
    static void Main()
    {
        long number = uint.Parse(Console.ReadLine());
        long mask = 7;
        long thirdFourthFifthBits = ((mask << 3) & number) >> 3; //1)  take the 3rd, 4th and 5th bits and save them
        long otherBits = ((mask << 24) & number) >> 24;          //2)  take the 24th, 25th and 26th bits and save them
        number = ~(mask << 24) & number;                         //3)  make the 24th, 25th, 26th bits equal to 0
        number = ~(mask << 3) & number;                          //4)  make the 3rd, 4th, 5th bits equal to 0
        number = (thirdFourthFifthBits << 24) | number;          //5)  fill the 24th, 25th, 26th with the new values
        number = (otherBits << 3) | number;                      //6)  fill the 3rd, 4th, 5th with the new values
        Console.WriteLine(number);
    }
}