You are playing a board game. The game consists of cards. The card is a table with the following features:
In each move, you can move from a block with coordinates to either of the following coordinates:
You want to know the number of ways you can move from the block to block .
Note: Print the answer .
Input format
Output format
In lines, print the answer that represents the number of ways you can move from the block to block .
Constraints
There is only one way to go from to and that is .
There is no way to go from to .
There are 2 ways to go from to .