There is a pile with stones. Two players take turns. On each turn, a player must split the pile into two parts of unequal sizes and take all the stones from the smaller part. A player who cannot make a move loses the game.
If you go first and want to guarantee a win, how many stones should you take on your first turn? If there is no winning move, output 0.
The number of stones in the pile (1 \le N \le 10000).
Output the number of stones you should take on your first turn to guarantee a win, or 0 if there is no winning move.
Example 1