Competitions

# Оператор розгалуження

# Game

There is a pile with **N** stones and **2** players. They plays by turns. In his turn the player must divide a pile into two unequal parts and take away smaller one. If it is impossible to do it, the player loses.

How many stones would you take if you expect to win the game, when you play as first player, or **0**, if you lose?

**Input**

The number of stones in the pile**N** (**1** ≤ **N** ≤ **10000**).

**Output**

Number of stones taken by you in the first turn, or **0** if you can't win the game.

Input example #1

7

Output example #1

3