#!/usr/bin/env luajit
require("deque")
require("utils")

opening = {
	["["] = "]",
	["{"] = "}",
	["<"] = ">",
	["("] = ")",
}

score = {
	["]"] = 2,
	["}"] = 3,
	[">"] = 4,
	[")"] = 1,
}

local scores = {}

for line in io.lines(arg[3]) do
	d = deque()
	for c in chars(line) do
		if opening[c] then
			d:append(opening[c])
		else
			if c ~= d:pop() then
				d = deque()
				break
			end
		end
	end
	local linescore = 0
	while d.size > 0 do
		linescore = linescore * 5 + score[d:pop()]
	end
	if linescore ~= 0 then
		table.insert(scores, linescore)
	end
end

table.sort(scores)
print(scores[(#scores + 1) / 2])