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 H,W;
char S[410][410];
int visited[410][410];
int ans=0;
int black,white;
int vx[4]={0,1,0,-1};
int vy[4]={1,0,-1,0};

void solve(int x,int y){
	if(visited[x][y]==1)return;
	
	char t;
	if(S[x][y]=='#'){
		t='.';
		black++;
	}else {
		t='#';
		white++;
	}
	visited[x][y]=1;
	
	for(int k=0;k<4;k++){
		int X=x+vx[k];
		int Y=y+vy[k];
		if(0<=X && X<H && 0<=Y && Y<W && S[X][Y]==t)solve(X,Y);
	}
	return;
}

int main(){
	scanf("%d%d",&H,&W);
	for(int i=0;i<H;i++)scanf("%s",S[i]);
	
	for(int i=0;i<H;i++)for(int j=0;j<W;j++){
		black=white=0;
		solve(i,j);
		ans+=black*white;
	}
	
	printf("%d\n",ans);
	
	return 0;
}