题目描述
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...
Input
Input is given from Standard Input in the following format:
H W
S_1
S_2
:
S_H
Output
Print the answer.
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 ..
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
输入格式
见题面 Input 部分
输出格式
见题面 Output 部分