#P4291. A Short problem

A Short problem

Problem Description

  According to a research, VIM users tend to have shorter fingers, compared with Emacs users.
  Hence they prefer problems short, too. Here is a short one:
  Given n (1 <= n <= 1018), You should solve for

g(g(g(n))) mod 109 + 7

  where
g(n) = 3g(n - 1) + g(n - 2)

g(1) = 1

g(0) = 0

Input

  There are several test cases. For each test case there is an integer n in a single line.
  Please process until EOF (End Of File).

Output

  For each test case, please print a single line with a integer, the corresponding answer to this case.

0 1 2
0 1 42837