updated

local slot = 2

turtle.select(1)
turtle.refuel()
turtle.select(2)
sleep(5)

local itemCount = turtle.getItemCount

if itemCount == 0 then

slot = slot+1
turtle.select(slot)
end


for i = 1, 129 do

turtle.placeDown()
turtle.forward()
end

turtle.forward()
turtle.turnRight()
turtle.forward()
end

for i = 1, 128 do

turtle.placeDown()
turtle.forward()
end

turtle.forward()
turtle.turnRight()
turtle.forward()
end

for i = 1, 129 do

turtle.placeDown()
turtle.forward()
end

turtle.forward()
turtle.turnRight()
turtle.forward()
end

for i = 1, 128 do

turtle.placeDown()
turtle.forward()
end