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 C (GCC 5.4.1) (judge verdict: Runtime Error)

#include <stdio.h>

int h,w,b[400][400],c[400][400],x[80000],y[80000];
long count(int, int),p;

long saki(int i, int j){
   long m;

   c[i][j]=1;m=0;
   x[p]=i;y[p]=j;p++;
   if (i>0 && b[i-1][j]==1 && c[i-1][j]==0) m+=count(i-1,j);
   if (i<h-1 && b[i+1][j]==1 && c[i+1][j]==0) m+=count(i+1,j);
   if (j>0 && b[i][j-1]==1 && c[i][j-1]==0) m+=count(i,j-1);
   if (j<w-1 && b[i][j+1]==1 && c[i][j+1]==0) m+=count(i,j+1);
   return m+1;
}

long count(int i, int j){
   long m;

   c[i][j]=1;m=0;
   x[p]=i;y[p]=j;p++;
   if (i>0 && b[i-1][j]==0 && c[i-1][j]==0) m+=saki(i-1,j);
   if (i<h-1 && b[i+1][j]==0 && c[i+1][j]==0) m+=saki(i+1,j);
   if (j>0 && b[i][j-1]==0 && c[i][j-1]==0) m+=saki(i,j-1);
   if (j<w-1 && b[i][j+1]==0 && c[i][j+1]==0) m+=saki(i,j+1);
   return m;
}

int main(){
   long n,k;
   int i,j;
   char s[401];
    
   scanf("%d %d",&h,&w);
   for (i=0;i<h;i++) {
      scanf("%s",s);
      for (j=0;j<w;j++) {
         if (s[j]=='#') b[i][j]=1;
         else           b[i][j]=0;
         c[i][j]=0;
      }
   }
   p=n=0;
   for (i=0;i<h;i++)
      for (j=0;j<w;j++) {
         if (b[i][j]) n+=count(i,j);
         for (k=0;k<p;k++) c[x[k]][y[k]]=0;
         p=0;
      }
   printf("%ld\n",n);
   return 0;
}