using System;
public class Program
{
public static void Main()
byte b = 0xFF ;
Console.WriteLine("byte " + Convert.ToString(b, 2));
unchecked
b &= (byte)(~(1 << 4));
}
Console.WriteLine("byte drop " + Convert.ToString(b, 2));
b |= 1 << 4;
Console.WriteLine("byte up " + Convert.ToString(b, 2));
