from collections import defaultdict

with open("input") as f:
    start_number = f.readline().strip()

print("Start:", start_number, "length:", len(start_number))

ATOM_TO_NUMBER = dict()
NUMBER_TO_ATOM = dict()
DECAY = dict()

# From https://web.archive.org/web/20061224154744/http://www.uam.es/personal_pdi/ciencias/omartin/Biochem.PDF
with open("atoms") as f:
    for line in f.readlines():
        columns = line.strip().split(" ")
        [_, atom, number] = columns[:3]
        NUMBER_TO_ATOM[number] = atom
        ATOM_TO_NUMBER[atom] = number
        DECAY[atom] = columns[3:]

start_atom = NUMBER_TO_ATOM[start_number]

print("Starting with atom:", start_atom)

ATOM_COUNT = defaultdict(int)
ATOM_COUNT[start_atom] = 1

for i in range(50):
    NEXT_ATOM_COUNT = defaultdict(int)
    for atom, count in ATOM_COUNT.items():
        for new_atom in DECAY[atom]:
            NEXT_ATOM_COUNT[new_atom] += count
    ATOM_COUNT = NEXT_ATOM_COUNT

    length = 0
    for atom, count in ATOM_COUNT.items():
        length += len(ATOM_TO_NUMBER[atom]) * count

    print("Round", i + 1, "len:", length)

print(length)