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 Java8 (OpenJDK 1.8.0) (judge verdict: Time Limit Exceeded)

import java.util.Scanner;
import java.util.Arrays;
import java.util.ArrayList;
public class Main{
	static char[][] a;
	static int h1;
	static int w1;
	static long sum;
	static int[][] b;
	static int l;
	public static void main(String[] args){
		Scanner sc = new Scanner(System.in);
		 h1 = sc.nextInt();
		 w1 = sc.nextInt();
		 a = new char[h1][w1];
		 b = new int[h1][w1];
		 l = 1;
		int count = 0;
		ArrayList<Integer> t = new ArrayList<Integer>();
		ArrayList<Integer> y = new ArrayList<Integer>();
		long ans = 0;
		for(int i = 0; i < h1; i++){
			String c = sc.next();
			for(int j = 0; j < w1; j++){
				a[i][j]=c.charAt(j);
				if(a[i][j]=='#'){
					count++;
					t.add(i);
					y.add(j);
				}
			}
		}
			for(int j=0; j<count; j++){
				if(a[t.get(j)][y.get(j)]=='#'){
					sum=0;
					dfs('#',t.get(j),y.get(j));
					ans+=sum;
					l++;
				}
			}
		
		System.out.println(ans);
	}
	public static void dfs(char q,int h, int w){
		
		
		if(b[h][w]==l){
			return;
		}
		if(q=='.'){
			sum++;
		}
		b[h][w]=l;
		if(h+1<h1 && q!=a[h+1][w]){
			dfs(a[h+1][w],h+1,w);
		}
		if(h-1>=0 && q!=a[h-1][w]){
			dfs(a[h-1][w],h-1,w);
		}
		if(w+1<w1 && q!=a[h][w+1]){
			dfs(a[h][w+1],h,w+1);
		}
		if(w-1>=0 && q!=a[h][w-1]){
			dfs(a[h][w-1],h,w-1);
		}
		
	}
}