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