Filling Shapes
题意翻译
输入$n$,求用三个方块组成的可旋转、翻转的“L”型砖块铺满$3 \times n$的网格的方案数。
题目描述
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.
![](https://cdn.luogu.com.cn/upload/vjudge_pic/CF1182A/3333a633cf4b745bcc0a00376e0a3a21d0b9762a.png) This picture describes when $ n = 4 $ . The left one is the shape and the right one is $ 3 \times n $ tiles.
输入输出格式
输入格式
The only line contains one integer $ n $ ( $ 1 \le n \le 60 $ ) — the length.
输出格式
Print the number of ways to fill.
输入输出样例
输入样例 #1
4
输出样例 #1
4
输入样例 #2
1
输出样例 #2
0
说明
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.