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: Accepted)

using System;
using System.Collections.Generic;
using System.Linq;
using System.IO;
//using System.Text;
//using System.Text.RegularExpressions;
//using System.Globalization;
//using System.Diagnostics;
using static System.Console;
//using System.Numerics;
//using static System.Math;
//using pair = Pair<int, int>;

class Program
{
    static void Main()
    {
        //SetOut(new StreamWriter(OpenStandardOutput()) { AutoFlush = false });
        new Program().solve();
        Out.Flush();
    }
    readonly Scanner cin = new Scanner();
    readonly int[] dd = { 0, 1, 0, -1, 0 }; //→↓←↑
    readonly int mod = 1000000007;
    void chmax<T>(ref T a, T b) where T : IComparable<T> { a = a.CompareTo(b) < 0 ? b : a; }
    void chmin<T>(ref T a, T b) where T : IComparable<T> { a = a.CompareTo(b) < 0 ? a : b; }

    int H, W;
    string[] S;
    int[][] C;

    void dfs(int ty, int tx, int c)
    {
        C[ty][tx] = c;
        for (int r = 0; r < 4; r++)
        {
            int y = ty + dd[r];
            int x = tx + dd[r + 1];
            if (y < 0 || y >= H || x < 0 || x >= W) continue;
            if (C[y][x] != 0 || S[ty][tx] == S[y][x]) continue;

            dfs(y, x, c);
        }
    }
    void solve()
    {
        H = cin.nextint;
        W = cin.nextint;
        S = new string[H];
        for (int i = 0; i < H; i++)
        {
            S[i] = ReadLine();
        }
        C = new int[H][];
        for (int i = 0; i < H; i++)
        {
            C[i] = new int[W];
        }

        int color = 1;
        for (int i = 0; i < H; i++)
        {
            for (int j = 0; j < W; j++)
            {
                if (C[i][j] == 0)
                {
                    dfs(i, j, color);
                    color++;
                }
            }
        }
        var P = new long[color];
        var Q = new long[color];
        for (int i = 0; i < H; i++)
        {
            for (int j = 0; j < W; j++)
            {
                if (S[i][j] == '.') P[C[i][j]]++;
                else Q[C[i][j]]++;
            }
        }

        long ans = 0;
        for (int i = 1; i < color; i++)
        {
            ans += P[i] * Q[i];
        }
        WriteLine(ans);
    }

}

class Scanner
{
    string[] s; int i;
    readonly char[] cs = new char[] { ' ' };
    public Scanner() { s = new string[0]; i = 0; }
    public string[] scan { get { return ReadLine().Split(); } }
    public int[] scanint { get { return Array.ConvertAll(scan, int.Parse); } }
    public long[] scanlong { get { return Array.ConvertAll(scan, long.Parse); } }
    public double[] scandouble { get { return Array.ConvertAll(scan, double.Parse); } }
    public string next
    {
        get
        {
            if (i < s.Length) return s[i++];
            string st = ReadLine();
            while (st == "") st = ReadLine();
            s = st.Split(cs, StringSplitOptions.RemoveEmptyEntries);
            i = 0;
            return next;
        }
    }
    public int nextint { get { return int.Parse(next); } }
    public long nextlong { get { return long.Parse(next); } }
    public double nextdouble { get { return double.Parse(next); } }
    public void join<T>(IEnumerable<T> values) { WriteLine(string.Join(" ", values)); }
}