railway

materials = 0

function checkFuel()
  if turtle.getFuelLevel() == 0 then
    selected = turtle.getSelectedSlot()
    turtle.select(16)
    turtle.refuel()
    turtle.select(selected)
  end
end

function countMaterials()
  for slot = 1,15 do
    turtle.select(slot)
    item = turtle.getItemDetail()
    if item ~= nil then
      materials = materials + item.count
    end
  end
end

countMaterials()
slot = 1
turtle.select(slot)

for i = 1,materials do
  checkFuel()
  if turtle.getItemCount() == 0 then
    slot = slot + 1
    turtle.select(slot)
  end

  turtle.placeDown()
  turtle.forward()
end