Furnace

x,y,z=1,1,0
dir=0
furnaces=5

function Forward()
	while not turtle.forward() do end
	if (dir%2)==0 then y=y-1+(dir%4)
	else x=x+2-(dir%4)
	end
end

function Up()
	while not turtle.up() do end
	z=z+1
end

function Down()
	while not turtle.down() do end
	z=z-1
end

function Right()
	turtle.turnRight()
	dir=(dir+1)%4
end

function Left()
	turtle.turnLeft()
	dir=(dir-1)%4
end

function EmptyInventory()
	Right() Forward() Forward() Forward() Forward()
	Left() Forward() Up() Up() Right()
	for i=1,16 do
		turtle.select(i)
		if turtle.getItemCount(i)>0 do
			local tries=0
			while not turtle.drop() do
				Up()
				tries=tries+1
			end
			for n=1,tries do Down() end
		end
	end
	turtle.select(1)
	Right() Down() Down() Forward() Right()
	Forward() Forward() Forward() Forward() Right()
end

function InventoryCount()
	local sum=0
	for i=1,16 do
		sum=sum+turtle.getItemCount(i)
	end
	return sum
end

while true do
	Right()
	turtle.suckUp()
	for i=1,furnaces-1 do
		Forward()
		turtle.suckUp()
	end
	Right() Right()
	while x>1 do Forward() end
	Right()
	if InventoryCount()>0 then EmptyInventory() end
end