input: Write a python function to multiply two matrices.
  assert matrix_multiply([[1, 2], [3, 4]], [[2, 0], [1, 2]]) == [[4, 4], [10, 8]]
  assert matrix_multiply([[1, 0], [0, 1]], [[5, 6], [7, 8]]) == [[5, 6], [7, 8]]
  assert matrix_multiply([[2, 4], [3, 4]], [[1, 2], [1, 0]]) == [[6, 4], [7, 6]]
output: def matrix_multiply(A, B):
      # Number of rows in A
      rowsA = len(A)
      # Number of columns in A and rows in B
      colsA = len(A[0])
      rowsB = len(B)
      # Number of columns in B
      colsB = len(B[0])
  
      # Initialize the result matrix with zeros
      result = [[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):
                  result[i][j] += A[i][k] * B[k][j]
  
      return result