#abc122d. [abc122_d]We Like AGC
[abc122_d]We Like AGC
Problem Statement
You are given an integer . Find the number of strings of length that satisfy the following conditions, modulo :
- 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.
Notes
A substring of a string is a string obtained by removing zero or more characters from the beginning and the end of .
For example, the substrings of ATCODER
include TCO
, AT
, CODER
, ATCODER
and (the empty string), but not AC
.
Constraints
Input
Input is given from Standard Input in the following format:
Output
Print the number of strings of length that satisfy the following conditions, modulo .
Sample Input 1
3
Sample Output 1
61
There are strings of length that do not contain characters other than A
, C
, G
and T
. Among them, only AGC
, ACG
and GAC
violate the condition, so the answer is .
Sample Input 2
4
Sample Output 2
230
Sample Input 3
100
Sample Output 3
388130742
Be sure to print the number of strings modulo .