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 PyPy3 (2.4.0) (judge verdict: Runtime Error)

h,w=[int(j) for j in input().split()]
s=[input()for i in range(h)]
ans=0
def f(i,j,se):
    se.add((i,j))
    res=0
    b=True
    for x,y in [(1,0),(-1,0),(0,1),(0,-1)]:
        p,q=i+x,j+y
        if 0<=p<h and 0<=q<w:
            if s[p][q]!=s[i][j] and (p,q) not in se:
                b=False
                res+=f(p,q,se)
    if b:
        if s[i][j]==".":
            return 1
        else:
            return 0
    else:
        if s[i][j]==".":
            return res+1
        else:
            return res

for i in range(h):
    for j in range(w):
        if s[i][j]=="#":
            ans+=f(i,j,set())

print(ans)