# Gardener-painter

Very easy

Execution time limit is 1 second

Runtime memory usage limit is 64 megabytes

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.

## Examples

Input #1

Answer #1

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