1class RunewordsCalculator:
 2    def __init__(self, runewords: dict) -> None:
 3        self.recipes = [[name, recipe, False] for name, recipe in runewords.items()]
 4        self.available_runes = []
 5
 6    def add_runes(self, runes: list) -> None:
 7        self.available_runes.extend(runes)
 8
 9    def __iter__(self):
10        return self
11
12    def _can_build(self, recipe: tuple) -> bool:
13        it = iter(self.available_runes)
14        return all(rune in it for rune in recipe)
15
16    def __next__(self) -> str | None:
17        remaining_recipes = [r for r in self.recipes if not r[2]]
18        
19        if not remaining_recipes:
20            raise StopIteration
21
22        for recipe_data in self.recipes:
23            name, recipe, issued = recipe_data
24            
25            if not issued:
26                if self._can_build(recipe):
27                    recipe_data[2] = True
28                    return name
29        
30        return None