A Short problem
TimeLimit:1000MS MemoryLimit:32768KB
64-bit integer IO format:%I64d
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 <= 10
18), You should solve for
g(g(g(n))) mod 10
9 + 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.