from pprint import pprint

with open('input.txt', 'r') as f:
    raw = [x.strip() for x in f.readlines()]
    initial_state = raw[0].split(' ')[-1]
    rules = dict()
    for rule in raw[2:]:
        x, y = rule.split(' => ')
        rules[x] = y
    
print(initial_state)
pprint(rules)

gens = 50000000000

start_idx = 0
state = initial_state
print(state)
for it in range(gens):
    if it % 10000 == 0:
        print('calc at', it, 'state len:', len(state), 'idx', start_idx)
        print(state)
    next = []
    state = '....' + state + '....'
    for i in range(2, len(state) - 2):
        seq = state[i-2:i+3]
        next.append(rules.get(seq) or '.')
    start_idx -= 2
    state = ''.join(next)
    start_idx += len(state) - len(state.lstrip('.'))
    state = state.strip('.')
    # print(' ' * (start_idx + 20) + state, start_idx)

res = 0
for i, pot_val in enumerate(state):
    pot_id = i + start_idx
    if pot_val == '#':
        res += pot_id
print(res)