using System;
class Lb
{
static void Main(string[] args)
{
while (true)
{
Console.Write ("Enter number:");
String s=Console.ReadLine(); uint x;
try
{
x = uint.Parse(s);
}
catch (OverflowException e)
{
Console.WriteLine("Number is too big");
continue; }
catch (Exception e)
{
Console.WriteLine("Error type of enter");
continue;
}
double l = Math.Log(x, 2);
Console.WriteLine("Lb({0}={1}",x,l);
}
}
}