I have python code. <pre> import itertools from decorators import timer from settings import MENU, CASH class Cocktail(object): def __init__(self, group, name, sell, count=0): self.group = group self.name = name self.sell = sell self.count = count class Check(object): def __init__(self, cash, menu=MENU): self.__cash = cash self.__cheapest_cocktail = 10000 self.__menu = self.__read_menu(menu) self.__matrix = self.__create_matrix() self.correct = [] def __read_menu(self, menu): result = [] for group in menu: key = group.keys()[0] for cocktail in group[key]: if self.__cheapest_cocktail > cocktail['sell']: self.__cheapest_cocktail = cocktail['sell'] result.append(Cocktail( key, cocktail['name'], cocktail['sell'], )) return result def __create_matrix(self): result = [] max_count = self.__cash // self.__cheapest_cocktail for cocktail in self.__menu: row = [] for i in range(0, max_count): row.append(Cocktail( cocktail.group, cocktail.name, cocktail.sell, i )) result.append(row) return result def find_combinations(self): for check in itertools.product(*self.__matrix): if sum([(c.sell * c.count) for c in check]) == self.__cash: self.correct.append(check) check = Check(CASH) check.find_combinations() </pre> check.__matrix size 80x25 It's works fine, but slow. Could anybody help make this faster.