aoc/01_frequencies.py

#!/usr/bin/env python3
import sys
changes = [int(line) for line in sys.stdin]

print(sum(changes))

n = 0
seen = set([n])
twice = None
while twice is None:
    for i in changes:
        n += i
        if n in seen:
            twice = n
            break
        seen.add(n)
print(twice)