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 Python (3.4.3) (judge verdict: Accepted)

def solve(H, W, grid):
    from collections import deque
    groups = [[0] * W for h in range(H)]
    v = 0 
    def search(M, h0, w0):
        nonlocal v
        count = [0, 0]
        Q = [(h0, w0)]
        groups[h0][w0] = M
        v+=1
        while Q:
            (h, w) = Q.pop()
            c = 1 - grid[h][w]
            count[1-c] += 1
            if h < H-1:
                if groups[h+1][w] == 0:
                    if grid[h+1][w] == c:
                        groups[h+1][w] = M
                        v += 1
                        Q.append((h+1, w))
                    else:
                        q.append((h+1, w))
            if h > 0:
                if groups[h-1][w] == 0:
                    if grid[h-1][w] == c:
                        groups[h-1][w] = M
                        v += 1
                        Q.append((h-1, w))
                    else:
                        q.append((h-1, w))
            if w > 0:
                if groups[h][w-1] == 0:
                    if grid[h][w-1] == c:
                        groups[h][w-1] = M
                        v += 1
                        Q.append((h, w-1))
                    else:
                        q.append((h, w-1))
            if w < W-1:
                if groups[h][w+1] == 0:
                    if grid[h][w+1] == c:
                        groups[h][w+1] = M
                        v += 1
                        Q.append((h, w+1))
                    else:
                        q.append((h, w+1))
        #print("search(%d,%d): %s"%(h0, w0, count))
        return count

    answer = 0
    m = 0
    q = deque()
    q.append((0,0))
    while q:
        h, w = q.pop()
        if groups[h][w] == 0:
            m+=1
            b, w = search(m, h, w)
            answer += b * w
    #for h in range(H): print(*groups[h])
    return answer

def main():
    import sys
    input = sys.stdin.readline
    H, W = map(int, input().split())

    grid = [[0]]*H
    for i in range(H):
        grid[i] = [1 if c == '#' else 0 for c in input().rstrip()]
    print(solve(H, W, grid))

main()