while true do
  while turtle.getItemCount(2) > 0 do
    turtle.select(1)
    success = true
    while not turtle.compare() do
      turtle.select(3)
      if turtle.compare() then
        success = false
        turtle.select(2)
        turtle.dig()
        turtle.place()
      end
      turtle.select(1)
      sleep(0.2)
    end
    if success then
      turtle.select(2)
      turtle.dig()
      turtle.place()
      turtle.select(1)
      turtle.dropDown(1)
      sleep(0.5)
    end
  end
  sleep(5)
end
