--io.input("test")
io.input("input")

function compare(left, right)
  local t = { l = type(left), r = type(right) }
  if t.l == "number" and t.r == "number" then
    if left < right then return true
    elseif left > right then return false
    else return nil
    end
  elseif t.l ~= t.r then
    if t.l == "number" then
      return compare( {left}, right )
    else
      return compare( left, {right} )
    end
  elseif t.l and t.r then -- two lists
    local i = 1
    while i <= #left or i <= #right do
      local leftE = left[i]
      local rightE = right[i]
      if not rightE and leftE then
        return false
      elseif not leftE and rightE then
        return true
      end
      local isCorrect = compare(leftE, rightE)
      if isCorrect == nil then
        i = i+1
      else return isCorrect
      end
    end
    return nil
  end
end

local pair = {}
local index = 1
local count = 0
local packets = { }
for line in io.lines() do
  if line == "" then
    pair = {}
    index = index + 1
    goto continue
  end

  -- hehe, convert to lua table and ingest
  local t = line:gsub("%[","{"):gsub("%]","}")
  local s = "return " .. t
  local packet = load(s)()

  table.insert( packets, packet )

  if not pair.l then
   pair.l = packet
   --print("left:", t)
  else
   pair.r = packet
  -- print("right:", t)
   local correct = compare( pair.l, pair.r )
   --print("pair", index, correct)
   if correct then count = count + index end
  end

  ::continue::
end

print("part 1", count)

function tableToString(t)
  local s = "{"
  for i, v in ipairs(t) do
    if type(v)=="table" then
     s = s .. tableToString(v)
    else
     s = s .. tostring(v)
    end
    if i<#t then s = s .. "," end
  end
  s = s .. "}"
  return s
end

-- part 2
table.insert(packets, {{2}})
table.insert(packets, {{6}})
table.sort( packets, compare )
local d1, d2
for i, p in ipairs(packets) do
  local ip = p[1]
  if ip and type(ip)=="table" and #ip == 1 and #p == 1 then
    if ip[1] == 2 then d1 = i
    elseif ip[1] == 6 then d2 = i end
  end
end

print("part 2", d1*d2)