input: 
  def matrix_multiplication(A, B):  
      rows_A = len(A)  
      cols_A = len(A[0])  
      rows_B = len(B)  
      cols_B = len(B[0])  
      result = [[0 for i in range(cols_B)] for j in range(rows_A)]  
      for i in range(rows_A): 
          for j in range(cols_B): 
              for k in range(cols_A): 
                  result[i][j] += A[i][k] * B[k][j] 
      return result
  
  # Example test cases
  # >>> matrix_multiplication([[1, 2], [3, 4]], [[5, 6], [7, 8]])
  # [[19, 22], [43, 50]]
  # >>> matrix_multiplication([[1, 2, 3], [4, 5, 6]], [[7, 8], [9, 10], [11, 12]])
  # [[58, 64], [139, 154]]
  
output:     rows_A = len(A)  
      cols_A = len(A[0])  
      rows_B = len(B)  
      cols_B = len(B[0])  
      result = [[0 for i in range(cols_B)] for j in range(rows_A)]  
      for i in range(rows_A): 
          for j in range(cols_B): 
              for k in range(cols_A): 
                  result[i][j] += A[i][k] * B[k][j] 
      return result