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L = [l.strip() for l in open("input").readlines()]
path = L[0]
nodes = dict(
(p := n.split(" = ")) and (p[0], p[1][1:-1].split(", ")) for n in L[2:]
)
def part1(start):
steps = 0
curr = start
while True:
d = path[steps % len(path)]
curr = nodes[curr][0 if d == "L" else 1]
steps += 1
if curr[2] == "Z":
return steps
def lcm(steps):
bi_gcd = lambda m, n: m if not n else bi_gcd(n, m % n)
res = steps[0]
for s in steps[1:]:
res = s * (res // bi_gcd(res, s))
return res
def part2():
steps = []
curr = [k for k in nodes.keys() if k[2] == "A"]
for s in curr:
steps.append(part1(s))
# modulo ring yay
return lcm(steps)
print(part1("AAA"))
print(part2())
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