Minimum Distance Between Metallic Objects

You are given an n x m grid containing characters. Each cell of the grid contains either a dot . or an uppercase letter M representing a metallic object. Your task is to compute the minimum Manhattan distance between any two metallic objects.

The Manhattan distance between two points \((r_1, c_1)\) and \((r_2, c_2)\) is defined as:

\( |r_1 - r_2| + |c_1 - c_2| \)

You must read the grid from the standard input and output a single integer representing the minimum distance between any two metallic objects.

inputFormat

The input is read from standard input (stdin) and has the following format:

• The first line contains two integers n and m — the number of rows and columns in the grid, respectively.
• The next n lines each contain a string of m characters where each character is either . or M.

It is guaranteed that there are at least two metallic objects (M) in the grid.

outputFormat

Output to standard output (stdout) a single integer — the minimum Manhattan distance between any two metallic objects in the grid.

3 4
....
.M..
...M

3