ProductList solution to cassidoo puzzle

productlist.py

import math

class ProductList:
  def __init__(self):
    self.numbers = []
  
  def add(self, number):
    self.numbers.append(number)

  def product(self, m):
    factors = self.numbers[::-1][:m]
    return math.prod(factors)
    
pl = ProductList()
pl.add(1)
pl.add(2)
pl.add(3)
pl.add(4)
prod_3 = pl.product(3)
prod_2 = pl.product(2)

print(prod_2, prod_3)