#!/usr/bin/env python import collections import sys Graph = dict[int, set[int]] def solve(input: str) -> int: def parse_ordering(input: str) -> Graph: graph: Graph = collections.defaultdict(set) for l in input.splitlines(): lhs, rhs = map(int, l.split("|")) graph[lhs].add(rhs) return graph def parse_updates(input: str) -> list[list[int]]: return [[int(n) for n in line.split(",")] for line in input.splitlines()] def parse(input: str) -> tuple[Graph, list[list[int]]]: ordering, updates = input.split("\n\n") return parse_ordering(ordering), parse_updates(updates) def validate_update(ordering: Graph, update: list[int]) -> bool: for i in range(len(update)): for j in range(i + 1, len(update)): lhs, rhs = update[i], update[j] if lhs in ordering[rhs]: return False return True def get_middle(update: list[int]) -> int: assert len(update) % 2 == 1 # Sanity check return update[len(update) // 2] ordering, updates = parse(input) return sum( get_middle(update) for update in updates if validate_update(ordering, update) ) def main() -> None: input = sys.stdin.read() print(solve(input)) if __name__ == "__main__": main()