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: Wrong Answer)

#include<stdio.h>
int Y[]={0,1,0,-1};
int X[]={1,0,-1,0};
int main(){
  int h,w,i,j,k,a,b,c=0,y[410*410],x[410*410],ny,nx,t,r,f[410][410]={};
  char s[410][410]={};
  scanf("%d %d",&h,&w);
  for(i=0;i<h;i++)scanf(" %s",s[i+1]+1);
  for(i=1;i<=h;i++){
    for(j=1;j<=w;j++){
      if(f[i][j])continue;
      a=b=0;
      f[y[t=0]=i][x[0]=j]=1;
      for(r=1;r-t;t++){
	if(s[y[t]][x[t]]=='.')a++;
	else                  b++;
	for(k=0;k<4;k++){
	  ny=y[t]+Y[k];
	  nx=x[t]+X[k];
	  if(f[ny][nx]==1)continue;
	  if(s[ny][nx]+s[y[t]][x[t]]-'#'-'.')continue;
	  f[y[r]=ny][x[r]=nx]=1;
	  r++;
	}
      }//printf("%d %d\n",a,b);
      c+=a*b;
    }
  }
  printf("%d\n",c);
  return 0;
}