input: Write a python function to perform matrix multiplication.
  assert matrixMultiplication([[1,2,3], [4,5,6], [7,8,9]], [[9,8,7], [6,5,4], [3,2,1]]) == [[30, 24, 18], [84, 69, 54], [138, 114, 90]]
  assert matrixMultiplication([[1,0,0], [0,1,0], [0,0,1]], [[5,4,3], [2,1,0], [9,8,7]]) == [[5, 4, 3], [2, 1, 0], [9, 8, 7]]
  assert matrixMultiplication([[1,2], [3,4]], [[2,0], [1,2]]) == [[4, 4], [10, 8]]
output: def matrixMultiplication(A, B):
      # Number of rows in A
      rowsA = len(A)
      # Number of columns in A (or number of rows in B)
      colsA = len(A[0])
      # Number of columns in B
      colsB = len(B[0])
      
      # Initialize the result matrix with zeros
      C = [[0 for _ in range(colsB)] for _ in range(rowsA)]
      
      # Perform matrix multiplication
      for i in range(rowsA):
          for j in range(colsB):
              for k in range(colsA):
                  C[i][j] += A[i][k] * B[k][j]
      
      return C