Minimum number of islands

You are mapping a faraway planet with a satellite. The planet's surface is a grid, and the satellite captured one image of that surface. Each grid cell is land (written as 'L'), water (written as 'W'), or covered by clouds (written as 'C'). A cell covered by clouds can be either land or water, and you cannot tell which.

An island is a region of land cells in which every two cells are connected to each other by a path that only moves up, down, left, or right.

Given the image, find the smallest number of islands that is consistent with it.

The first line contains the number of rows $r$ and the number of columns $c$ of the image ($1 \le r, c \le 50$).

Each of the next $r$ lines contains exactly $c$ characters. Every character is 'L' for land, 'W' for water, or 'C' for clouds.

Print a single integer, the smallest possible number of islands.