MazeRowControl

modem = peripheral.wrap("top")
modem.open(10)

local f = fs.open("row.lua", "r")
row = tonumber(f.readLine())
f.close()

function get(str, index)
  i = 1
  for cur in str:gmatch("%S+") do
    if i == index then
      return cur
    end
    i = i + 1
  end

  return "0"
end

while true do
  e, _, _, _, message = os.pullEvent("modem_message")
  value = tonumber(get(message, row))
  print(value)
  rs.setBundledOutput("back", value)
end