1 人解决，3 人已尝试。
1 份提交通过，共有 55 份提交。
9.9 EMB 奖励。
单点时限: 10.0 sec
内存限制: 256 MB
A tatami mat, a Japanese traditional floor cover, has a rectangular form with aspect ratio 1:2. When spreading tatami mats on a floor, it is prohibited to make a cross with the border of the tatami mats, because it is believed to bring bad luck.
Your task is to write a program that reports how many possible ways to spread tatami mats of the same size on a floor of given height and width.
The input cosists of a line which contains two integers H and W in this order, separated with a single space. H and W are the height and the width of the floor respectively. The length of the shorter edge of a tatami mat is regarded as a unit length.
You may assume 0 < H,W <= 20.
Print the number of possible ways to spread tatami mats in one line.
3 4 /* 4 4 */
4 /* 2 */
1 人解决，3 人已尝试。
1 份提交通过，共有 55 份提交。
9.9 EMB 奖励。