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CF1027E.Inverse Coloring
Inverse Coloring
You are given a square board, consisting of rows and columns. Each tile in it should be colored either white or black.
Let's call some coloring beautiful if each pair of adjacent rows are either the same or different in every position. The same condition should be held for the columns as well.
Let's call some coloring suitable if it is beautiful and there is no rectangle of the single color, consisting of at least tiles.
Your task is to count the number of suitable colorings of the board of the given size.
Since the answer can be very large, print it modulo .
Input
A single line contains two integers and (, ) — the number of rows and columns of the board and the maximum number of tiles inside the rectangle of the single color, respectively.
Output
Print a single integer — the number of suitable colorings of the board of the given size modulo .
Note
Board of size is either a single black tile or a single white tile. Both of them include a rectangle of a single color, consisting of tile.
Here are the beautiful colorings of a board of size that don't include rectangles of a single color, consisting of at least tiles:

The rest of beautiful colorings of a board of size are the following:

Samples
1 1
0
2 3
6
49 1808
359087121
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