input: Write a function to multiply two matrices A and B, producing a matrix C where each element is the product of the corresponding elements of A and B. If the matrices cannot be multiplied due to incompatible dimensions, return the string "Matrix multiplication not possible".
  assert matrixMultiplication([[3, 4], [1, 2]], [[7, 5], [0, 1]])==[[21, 20], [0, 2]]
  assert matrixMultiplication([[1, 2, 3]], [[4], [5], [6]])==[[32]]
  assert matrixMultiplication([[1, 2], [3, 4]], [[5, 6], [7, 8], [9, 10]])=="Matrix multiplication not possible"
  assert matrixMultiplication([], [])==[]
output: def matrixMultiplication(A, B):
      if len(A) == 0 or len(B) == 0 or len(A[0]) != len(B[0]):
          return "Matrix multiplication not possible"
      C = [[A[i][j] * B[i][j] for j in range(len(A[0]))] for i in range(len(A))]
      return C