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: Runtime Error)

def dfs(x, y, c):
	d[x, y] = c
	if S[x][y] == '#':
		black[c] = black.get(c, 0) + 1
	else:
		white[c] = white.get(c, 0) + 1
	for u, v in [(x - 1, y), (x + 1, y), (x, y - 1), (x, y + 1)]:
		if u < 0 or u >= H or v < 0 or v >= W:
			continue
		if d[u, v] != -1:
			continue
		if S[x][y] !=  S[u][v]:
			dfs(u, v, c)

H, W = map(int, input().split())
S = []
for i in range(H):
	S.append(input())
d = {}
for i in range(H):
	for j in range(W):
		d[i, j] = -1
count = 0
black = {0: 0}
white = {0: 0}
for i in range(H):
	for j in range(W):
		if d[i, j] == -1:
			dfs(i, j, count)
			count += 1
			black[count] = 0
			white[count] = 0
ans = 0
for i in range(count):
	ans += black[i] * white[i]
print(ans)