function refuel()
	if turtle.getFuelLevel() < 10 then
		turtle.select(1)
		turtle.refuel(1)
	end
end

function harvest_row()
	for i=1, 128 do
		refuel()
		turtle.dig()
		turtle.forward()
		turtle.digDown()
	end
end

function harvest_section()
	harvest_row()
	turtle.forward()
	turtle.turnLeft()
	turtle.forward()
	turtle.turnLeft()
	harvest_row()
	turtle.forward()
end

while true do
	turtle.select(1)
	while turtle.getItemCount() < 16 do
		turtle.suckDown(16 - turtle.getItemCount())
	end
	harvest_section()
	refuel()
	for v=2, 16 do
		turtle.select(v)
		turtle.dropDown()
	end
	turtle.turnLeft()
	turtle.forward()
	turtle.turnLeft()
	sleep(60 * 5)
end