startup

while true do
  while not turtle.detectDown() do
    turtle.down()
  end
  turtle.back()

  if not turtle.detect() then
    turtle.select(16)
    turtle.forward()
    turtle.place()
    turtle.back()
    turtle.place()
  end

  turtle.select(1)
  if turtle.compare(1) then
    turtle.dig()
    turtle.forward()
    while turtle.detectUp() do
      turtle.dig()
      turtle.digUp()
      turtle.up()
    end
    while not turtle.detectDown() do
      turtle.down()
    end
    turtle.back()
    for i = 2,15 do
      if turtle.getItemCount(i) >0 then
        turtle.select(i)
        turtle.dropDown()
      end
    end
  end
  sleep(1)
end