Problem:
Score : 300 points

Problem Statement

There is a grid with H rows and W columns, where each square is painted black or white.

You are given H strings S_1, S_2, ..., S_H, each of length W.
If the square at the i-th row from the top and the j-th column from the left is painted black, the j-th character in the string S_i is #; if that square is painted white, the j-th character in the string S_i is ..

Find the number of pairs of a black square c_1 and a white square c_2 that satisfy the following condition:

There is a path from the square c_1 to the square c_2 where we repeatedly move to a vertically or horizontally adjacent square through an alternating sequence of black and white squares: black, white, black, white...

Constraints

1 \leq H, W \leq 400

|S_i| = W (1 \leq i \leq H)

For each i (1 \leq i \leq H), the string S_i consists of characters # and ..

Input

Input is given from Standard Input in the following format:

H W
S_1
S_2
:
S_H

Output

Print the answer.

Sample Input 1

3 3
.#.
..#
#..

Sample Output 1

10

Some of the pairs satisfying the condition are ((1, 2), (3, 3)) and ((3, 1), (3, 2)), where (i, j) denotes the square at the i-th row from the top and the j-th column from the left.

Sample Input 2

2 4
....
....

Sample Output 2

0

Sample Input 3

4 3
###
###
...
###

Sample Output 3

6

Solution in C# (Mono 4.6.2.0) (judge verdict: Runtime Error)

using System;
using System.Collections.Generic;
    struct Point{
        public int x;
        public int y; 
        public Point(int x,int y)
        {
            this.x = x;
            this.y = y;
        }
    }
class Program
{
    static void Main(string[] args)
    {
        var hw = Console.ReadLine().Split(' ');
        var h = int.Parse(hw[0]);
        var w = int.Parse(hw[1]);
        var s = new char[h][];
        for (int r = 0; r < h; r++)
        {
            s[r] = new char[w];
            var ss = Console.ReadLine().ToCharArray();
            for (int c = 0; c < w; c++)
            {
                s[r][c] = ss[c];
            }
        }
        var dic = new Dictionary<Point, Point>();

        for (int r = 0; r < h; r++)
        {
            for (int c = 0; c < w; c++)
            {
                for (int r2 = 0; r2 < h; r2++)
                {
                    for (int c2 = 0; c2 < w; c2++)
                    {
                        var con = false;
                        foreach (var v in dic)
                        {
                            if (v.Key.x == r && v.Key.y == c && v.Value.x == r2 && v.Value.y == c2)
                            {
                                con = true;
                                break;
                            }
                            if (v.Key.x == r2 && v.Key.y == c2 && v.Value.x == r && v.Value.y == c)
                            {
                                con = true;
                                break;
                            }
                        }
                        if ((r == r2 && c == c2) || con) continue;
                        if (s[r][c] != s[r2][c2])
                        {
                            dic.Add(new Point(r, c), new Point(r2, c2));
                        }
                    }
                }
            }
        }

        Console.WriteLine(dic.Count);

    }
}