Problems
Gardener-painter
Gardener-painter
Gardener has to paint trees after planting. He has paint of three colour: white, blue and orange.
How many ways he can paint of $N$ trees, if not any two the same colours can be side by side?
Input
The quantity of trees is $N$$(1 ≤ N ≤ 50)$.
Output
The quantity of ways of paint.
Input example #1
3
Output example #1
12