Sum of all Submatrices 

Problem Description
Given a 2D Matrix A of dimensions N*N, we need to return sum of all possible submatrices.
Input Format
Single argument representing a 2-D array A of size N x N.
Output Format
Return an integer denoting the sum of all possible submatrices in the given matrix.
Example Input
A = [ [1, 1]
[1, 1] ]
Example Output
16
Example Explanation
Number of submatrices with 1 elements = 4, so sum of all such submatrices = 4 * 1 = 4
Number of submatrices with 2 elements = 4, so sum of all such submatrices = 4 * 2 = 8
Number of submatrices with 3 elements = 0
Number of submatrices with 4 elements = 1, so sum of such submatrix = 4
Total Sum = 4+8+4 = 16