function parse_input()
    rules = []
    manuals = []
    open("input.txt") do f
        for line in readlines(f)
            if length(line) == 0
                continue
            end
            if '|' in line
                num1, num2 = split(line, '|')
                push!(rules, (parse(Int, num1), parse(Int, num2)))
            else
            push!(manuals, map(s -> parse(Int, s), split(line, ',')))
            end
        end
    end
    return rules, manuals
end

function check_rules(rules, page)
    for (n1, n2) in rules
        if !(n1 in page) || !(n2 in page)
            continue
        end
        n1_pos = findfirst(item -> item == n1, page)
        n2_pos = findfirst(item -> item == n2, page)
        if n1_pos > n2_pos
            return 0
        end
    end
    return page[(length(page) ÷ 2) + 1]
end

function main()
    rules, manuals = parse_input()
    result = sum(map(m -> check_rules(rules, m), manuals))
    println(result)
end

if abspath(PROGRAM_FILE) == @__FILE__
    main()
end