3placev

function clearInv()
	turtle.digDown()
	local slot=2
	while slot <= 16 do
   	 	if turtle.getItemCount(slot) > 0 then
        	turtle.select(slot)
          	turtle.dropDown()
    	end
    	slot = slot + 1
	end
	turtle.select(2)
end

function forward()
	if turtle.forward() then
		return
	else
		turtle.dig()
		forward()
	end
end

function up()
	if turtle.up() then
		return
	else
		turtle.digUp()
		up()
	end
end

function down()
	if turtle.down() then
		return
	else
		turtle.digDown()
		down()
	end
end

function refuel()
	turtle.select(1)
	turtle.refuel()
	turtle.select(2)
end

function place_down()
	local slot=offset
	while slot <= offset + 3 do
   	 	if turtle.getItemCount(slot) > 0 then
        	turtle.select(slot)
          	turtle.placeDown()
			return
    	end
    	slot = slot + 1
	end
end

function place_up()
	local slot=offset
	while slot <= offset + 3 do
   	 	if turtle.getItemCount(slot) > 0 then
        	turtle.select(slot)
          	turtle.placeUp()
			return
    	end
    	slot = slot + 1
	end
end

local bottom=10
local top=70
offset=5
local y=10
refuel()

while y <= top do
	print(turtle.getFuelLevel())
	place_down()
	up()
	y = y+1
end
forward()
offset=9
while y >= bottom do
	down()
	place_up()
	y=y-1
end

forward()
offset=13
while y <= top do
	place_down()
	up()
	y=y+1
end

forward()
while y >= bottom do
	down()
	y=y-1
end