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())
L=[list(input())for i in range(H)]
#print(L)

P=[i for i in range(H*W)]
size=[[0,0]for i in range(H*W)]

for i in range(H):
    for j in range(W):
        if L[i][j]==".":
            size[i*W+j][0]+=1
        else:
            size[i*W+j][1]+=1
#print(size)

def find(z):
    if  z==P[z]:
        return z
    else:
        return find(P[z])
def union(x,y):
    X=find(x)
    Y=find(y)
    if sum(size[X])>=sum(size[Y]):
        P[Y]=P[X]
        size[X][0]+=size[Y][0]
        size[X][0]+=size[Y][1]
    else:
        P[X]=P[Y]
        size[Y][0]+=size[X][0]
        size[Y][0]+=size[X][1]
        
for i in range(H):
    for j in range(W):
        if j+1<=W-1:
            
            if L[i][j]!=L[i][j+1]:
                
                if find(i*W+j)!=find(i*W+j+1):
                    #print(i,j)
                    union(i*W+j,i*W+j+1)
        if i+1<=H-1:
            if L[i][j]!=L[i+1][j]:
                if find((i)*W+j)!=find((i+1)*W+j):
                    union(i*W+j,(i+1)*W+j)
BW=[[0,0]for i in range(H*W)]
for i in range(H):
    for j in range(W):
        if L[i][j]==".":
            BW[find(i*W+j)][0]+=1
        else:
            BW[find(i*W+j)][1]+=1

ans=0
for i in range(H):
    for j in range(W):
        if P[i*W+j]==i*W+j:
            ans+=BW[i*W+j][0]*BW[i*W+j][1]
#print(P)
#print(BW)
print(ans)