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)

# coding: utf-8
# Your code here!

#n = int(input())
import sys

sys.setrecursionlimit(100000)

h,W = [int(i) for i in input().split()]
#b = [i for i in input().split()]
board = []
for _ in range(h):
    board.append(input())

checked = [[0]*W for i in range(h)]

dx=[ 0, 1, 0,-1]
dy=[ 1, 0,-1, 0]

ans = 0

def dfs(x,y,b,w):
    for i in range(4):
        nx = x + dx[i]
        ny = y + dy[i]
#        print(nx,ny)
#        print(checked)
        if nx < 0 or nx >= h or ny < 0 or ny >= W or checked[nx][ny]==1:
            continue
        if board[x][y] == board[nx][ny]:
            continue
#        print("ok")
        checked[nx][ny]=1
        if board[nx][ny] == '#':
            b+=1
        else:
            w+=1
        b1,w1 = dfs(nx, ny,0,0)
        b+=b1
        w+=w1
#    print(x,y,b,w)
    return b,w

#print(dfs(0,0,0,0))

for i in range(h):
    for j in range(W):
        if checked[i][j] == 1:
            continue
        checked[i][j] = 1
        if board[i][j] == '#':
            b2 = 1; w2=0
        else:
            b2 = 0; w2=1
        b1,w1 = dfs(i,j,b2,w2)
#        print(b1,w1)
        ans += b1*w1

print(ans)