rules, updates = DATA.read.split("\n\n")

rules = rules.scan(/(\d+)\|(\d+)/).map { _1.map(&:to_i) }
updates = updates.lines.map { _1.split(?,).map(&:to_i) }

correct, incorrect = updates.partition {|pages|
  pages.each_cons(2).all? { rules.include?(_1) }
}

pp correct.sum { _1[_1.length/2] }

pp incorrect.map {|pages|
  pages.sort {|a,b| rules.include?([a,b]) ? -1 : 1 }
}.sum { _1[_1.length/2] }

__END__
47|53
97|13
97|61
97|47
75|29
61|13
75|53
29|13
97|29
53|29
61|53
97|53
61|29
47|13
75|47
97|75
47|61
75|61
47|29
75|13
53|13

75,47,61,53,29
97,61,53,29,13
75,29,13
75,97,47,61,53
61,13,29
97,13,75,29,47