Matrix Multiplication

1. The main condition of matrix multiplication is that the number of columns of the 1st matrix must equal to the number of rows of the 2nd one.
2. As a result of multiplication you will get a new matrix that has the same quantity of rows as the 1st one has and the same quantity of columns as the 2nd one.
3. For example if you multiply a matrix of "n" * "k" by "k" * "m" size you"ll get a new one of "n" * "m" dimensions.

Create a function that takes 2 x 2D array (matrix A, matrixB) as an argument and returns a 2D array (matrix C). C = A*B.

• If the number of columns of the 1st matrix isn't equal to the number of rows of the 2nd: return "ERROR".
• Or the number of rows of the 1st matrix isn't equal to the number of columns of the 2nd: return "ERROR".

Examples

mul([
  [1, 2, 3],
  [4, 5, 6],
  [7, 8, 9]
], [
  [1, 2, 3],
  [4, 5, 6],
  [7, 8, 9]
]) ➞ [
  [30, 36, 42],
  [66, 81, 96],
  [102, 126, 150]
]

Notes

N/A