Let's consider circle game.
From N children, numbered 1, 2, ..., N,
standing in circle every M-th is going to be removed
from circle and only the last child will be the winner.
For example when N = 6 and M = 5 then the children will
be removed in the order 5, 4, 6, 2, 3 and 1 will be winner.

There are two teams playing the game. Each team consists of K children.
In the circle the first K children are from the first team and the last
K children from the second one. You have to determine such minimal M that
all the players of the second team will be removed before
the children of the first team.

Input
The input consists of one line, containing K. 0 < K < 14.

Output
The output should contain M.

Input#1

4

Output#1

30

Author:
Student olympiad in Khmelnitski, March 2003
24 april 2003