A. Filling Shapes
time limit per test
1 second
memory limit per test
256 megabytes
input
standard input
output
standard output

You have a given integer $$$n$$$. Find the number of ways to fill all $$$3 \times n$$$ tiles with the shape described in the picture below. Upon filling, no empty spaces are allowed. Shapes cannot overlap.

This picture describes when $$$n = 4$$$. The left one is the shape and the right one is $$$3 \times n$$$ tiles.
Input

The only line contains one integer $$$n$$$ ($$$1 \le n \le 60$$$) — the length.

Output

Print the number of ways to fill.

Examples
Input
4
Output
4
Input
1
Output
0
Note

In the first example, there are $$$4$$$ possible cases of filling.

In the second example, you cannot fill the shapes in $$$3 \times 1$$$ tiles.