Bitmap Holes

Have the function BitmapHoles(strArr) take the array of strings stored in strArr, which will be a 2D matrix of 0 and 1's, and determine how many holes, or contiguous regions of 0's, exist in the matrix. A contiguous region is one where there is a connected group of 0's going in one or more of four directions: up, down, left, or right. For example: if strArr is ["10111", "10101", "11101", "11111"], then this looks like the following matrix:

1 0 1 1 1
1 0 1 0 1
1 1 1 0 1
1 1 1 1 1

For the input above, your program should return 2 because there are two separate contiguous regions of 0's, which create "holes" in the matrix. You can assume the input will not be empty.

Examples

Input: ["01111", "01101", "00011", "11110"]
Output: 3

Input: ["1011", "0010"]
Output: 2