Ksonya and the Two-Color Figure#11069
Ksonya received an infinite chessboard for her birthday, where each cell is colored either black or white. She wants to cut out a connected figure from it so that it contains exactly black cells and exactly white cells. The figure does not have to be completely filled, but it must be connected.
An example of a valid figure. It does not matter that the middle cell is empty. The main thing is that the figure is connected. This figure contains four white cells and four black cells.
An example of an invalid figure because it is not connected.
Help Ksonya find any such figure or determine that it does not exist.
The first line contains two integers and (0 \leq w, b \leq 100) — the number of white and black cells respectively.
If no solution exists, print a single number .
Otherwise, in the first line print two integers , (1 \leq n, m \leq 250) — the dimensions of the rectangle that contains the desired figure. It can be shown that if a solution exists, then there is a solution that fits within these constraints.
Then print lines with characters each — the description of the figure. If a cell of the rectangle is empty — print ., if the cell is white — print W, if it is black — print B.
The figure defined by this rectangle must be connected, contain exactly white and exactly black cells, and be colored in a chess pattern (neighbors of a white cell can only be empty or black cells, and neighbors of a black cell can only be empty or white cells).
Example 1
Example 2
Example 3
Solutions that work correctly for w = b will receive at least points.
Solutions that work correctly for \max(w, b) \le 2 \cdot \min(w, b) will receive at least points.