while true do
 turtle.select(9)
 if turtle.compare() then
  turtle.select(1)
  while turtle.compare() do
   turtle.dig()
   turtle.digUp()
   turtle.up()
  end
  while not turtle.detectDown() do
   turtle.down()
  end
  turtle.turnLeft()
  turtle.turnLeft()
  while turtle.getItemCount(1) > 0 do
   turtle.drop(1)
  end
  turtle.turnLeft()
  turtle.turnLeft()
  turtle.select(2)
  turtle.place()
 end
end