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)

h,w = map(int, input().split())
m = [input() for _ in range(h)]
seen = [[0]*w for _ in range(h)]
dxy =[(1,0),(0,1),(-1,0),(0,-1)]
cnt = 0
for i in range(h):
  for j in range(w):
    if not seen[i][j]:
      bcnt,wcnt = 0,0
      q = [(i,j)]
      while q:
        y,x = q.pop()
        if seen[y][x]:
          continue
        if m[y][x] == "#":
          bcnt += 1
        else:
          wcnt += 1
        seen[y][x] = 1
        for dx,dy in dxy:
          if 0<=x+dx<w and 0<=y+dy<h and not seen[y+dy][x+dx] and m[y+dy][x+dx] != m[y][x]:
            q.append((y+dy,x+dx))
      cnt += bcnt*wcnt
print(cnt)