import collections


def read_food():
    with open('day21/input') as reader:
        return reader.readlines()


food_as_text = read_food()

food = []
for f in food_as_text:
    ingredients, allergens = f[:-1].split(' (contains ')
    food.append((ingredients.split(' '), allergens[:-1].split(', ')))


def get_allergen_possibilities(food):
    allergen_possibilities = {}
    for ingredients, allergens in food:
        for a in allergens:
            if a not in allergen_possibilities.keys():
                allergen_possibilities[a] = set(ingredients)
            else:
                allergen_possibilities[a] = allergen_possibilities[a].intersection(set(ingredients))
    return allergen_possibilities


def get_all_ingredients_with_possible(allergen_possibilities):
    all_ingredients_with_possible = set()
    for i in allergen_possibilities.values():
        all_ingredients_with_possible = all_ingredients_with_possible.union(i)
    return all_ingredients_with_possible


def get_all_ingredients(food):
    all_ingredients = set()
    for ingredients, allergens in food:
        all_ingredients = all_ingredients.union(ingredients)
    return all_ingredients


def count_no_allergens(food, no_allergen):
    c = 0
    for ingredients, allergens in food:
        for i in ingredients:
            if i in no_allergen:
                c += 1
    return c


def find_allergens(allergen_possibilities):
    defined_allergens = {}
    while True:
        found_key, found_value = next((key, value) for key, value in allergen_possibilities.items() if len(value) == 1)
        ingredient_defined = list(found_value)[0]

        defined_allergens[found_key] = ingredient_defined

        del allergen_possibilities[found_key]
        for allergen in allergen_possibilities.keys():
            if ingredient_defined in allergen_possibilities[allergen]:
                allergen_possibilities[allergen].remove(ingredient_defined)

        if not allergen_possibilities:
            break

    return defined_allergens


allergen_possibilities = get_allergen_possibilities(food)
all_ingredients_with_possible = get_all_ingredients_with_possible(allergen_possibilities)
all_ingredients = get_all_ingredients(food)

no_allergen = all_ingredients.difference(all_ingredients_with_possible)

res = count_no_allergens(food, no_allergen)

print(res)

defined_allergens = find_allergens(allergen_possibilities)

ordered_by_insertion = collections.OrderedDict(sorted(defined_allergens.items()))

canonical_dangerous_ingredient_list = ','.join([v for v in ordered_by_insertion.values()])

print(canonical_dangerous_ingredient_list)