Painting a board

Write a program to paint several zones of an $n \times m$ board. Here, a zone is defined as a maximal set of adjoining cells, both horizontally and vertically.

Input

Input consists of several cases. Every case begins with the dimensions $n$ and $m$ , followed by $n$ lines with $m$ characters each. A character ‘#’ indicates a wall. A dot indicates an empty cell. A lowercase or uppercase letter indicates what must be used to fill that zone. Every zone has at most one letter. Suppose $3 \le n \le 30$ , $3 \le m \le 30$ , and that the borders of the board only have walls.

Output

For every case, print the result of painting the board, followed by an empty line.

Problem information

Author: Unknown
Translator: Salvador Roura

Generation: 2026-01-25T11:02:48.037Z