One can determine the Gray code by its number using a very simple function: G(x) = x xor (x div 2), where xor stands for bitwise exclusive OR (bitwise modulo 2 addition), and div means integer division. It is interesting to note that function G(x) is invertible, which means it is always possible to uniquely restore x given the value of G(x). Write a program to restore number x from the given value of G(x).

Input

The input file contains an integer number y, the value of G(x) (0≤y≤10⁹).

Output

The output file should contain a single integer x such that G(x) = y.

Samples

15

10

1723

1234

0

0