## 实木地板

 Grade Open Time Friday, 19 September 2014, 10:08 am Discount 0.8 Time Discount Friday, 26 September 2014, 10:08 am Allow late Yes Close Time Friday, 26 September 2014, 10:08 am Input file examsix.in Output file examsix.out

### 【英文原题】

The banquet hall of Computer Scientists' Palace has a rectangular form of the size M x N (1<=M<=9, 1<=N<=9). It is necessary to lay hardwood floors in the hall. There are wood pieces of two forms:

1) rectangles (2x1)

2) corners (squares 2x2 without one 1x1 square)

You have to determine X - the number of ways to cover the banquet hall.

Remarks. The number of pieces is large enough. It is not allowed to leave empty places, or to cover any part of a surface twice, or to saw pieces.

### 【样例输入】

2 3

### 【样例输出】

5

### 【来源】

Author: Herman "Smash" Narkaytis, Paul "Stingray" Komkoff

Resource: 5th Southern Subregional Contest. Saratov 2002