Description

The Golden Pig family is mainly composed of sows. A young sow can give birth to $2$ young sows and $2$ young boars in the second year, and from the third year onwards, she can give birth to $4$ young sows and $4$ young boars each year. Young boars are driven out of the family in their second year. The lifespan of a pig is only six years.
Currently, a new Golden Pig family is being formed: a young sow starts her own Golden Pig family.

Input Format

A single line containing a positive integer $n$ ($1 \leq n \leq 35$).

Output Format

A single line containing a positive integer: the number of members in the Golden Pig family in the $n$-th year.

Sample

3

19