Bishops

You are given an n × n chess board, with some black bishops on it.
Please place as many white bishops as possible is such a way that no
white bishop threatens another bishop, either black or white.

For instance, for the board to the left a possible solution is shown on
the board to the right.

Input

Input consists of several cases, each with n followed by n lines, each
one with n characters: ‘B’ for black bishops, and ‘.’ for empty cells.
Assume 1 ≤ n ≤ 1000.

Output

For every case, print any possible solution using ‘W’ for white bishops,
followed by a line with 20 dashes. Follow exactly the format of the
sample output.

Problem information

Author: Felix Miravé

Generation: 2026-01-25T12:03:06.505Z

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