#D10686. We Like AGC
We Like AGC
We Like AGC
You are given an integer N. Find the number of strings of length N that satisfy the following conditions, modulo 10^9+7:
- The string does not contain characters other than
A
,C
,G
andT
. - The string does not contain
AGC
as a substring. - The condition above cannot be violated by swapping two adjacent characters once.
Constraints
- 3 \leq N \leq 100
Input
Input is given from Standard Input in the following format:
N
Output
Print the number of strings of length N that satisfy the following conditions, modulo 10^9+7.
Examples
Input
3
Output
61
Input
4
Output
230
Input
100
Output
388130742
inputFormat
Input
Input is given from Standard Input in the following format:
N
outputFormat
Output
Print the number of strings of length N that satisfy the following conditions, modulo 10^9+7.
Examples
Input
3
Output
61
Input
4
Output
230
Input
100
Output
388130742
样例
4
230