#!/usr/bin/env python
# 2024 - Advent Of Code 5 - part 2

from math import floor

# file = 'input_example.txt'
file = 'input.txt'

updates = []
rules = {}
update = 0
with open(file, encoding="utf-8") as f:
    for line in f.read().splitlines():
        if line == '':
            update = 1
            continue
        if update == 0:
            before, after = line.split('|')
            if int(before) in rules:
                l = rules[int(before)]
                l.append(int(after))
                rules[int(before)] = l
            else:
                rules[int(before)] = [int(after)]
        else:
            updates.append([int(x) for x in line.split(',')])

#print(f'{rules=}')
#print(f'{updates=}')

good_updates = []
bad_updates = []
for update in updates:
    broken_rule = False
    for num, page in enumerate(update):
        if page in rules:
            for p in rules[page]:
                if p in update[0:num]:
                    broken_rule = True
                    break
    if not broken_rule:
        good_updates.append(update)
    else:
        bad_updates.append(update)

for update in bad_updates:
    working_update = update
    for num, page in enumerate(working_update):
        for u in working_update[:num]:
            if page in rules:
                if u in rules[page]:
                    working_update.remove(u)
                    working_update.insert(num, u)


accum = 0
print(f'# bad_updates {len(good_updates)}')
for u in bad_updates:
    accum += u[floor(len(u)/2)]

print(f'{accum=}')