peripheral.find("modem", rednet.open)

while true do
  local id, message = rednet.receive()

  if id ~= nil then
    local data = textutils.unserialise(message)
    local event = data["event"]

    if event == "target" then
      print(data["floor"])
    elseif event == "arrived" then
      print(data["floor"])
    end
  end
end