FoundryWorker[Top]

x = 0

slot = 2

function selectSlot()
    if turtle.getItemCount(slot) == 0 and slot < 16 then
        slot = slot + 1
    end
    turtle.select(slot)
end

print("+-------------------------------------+")
print("| Foundry Worker                      |")
print("+-------------------------------------+")
print("| Slot 1: Fuel                        |")
print("| Slot 2-16: Raw Materials            |")
print("+-------------------------------------+")
print("| Array length = ?                    |")
print("+-------------------------------------+")
l = tonumber(read())

while x < l do
    turtle.select(1)
    turtle.refuel()
    selectSlot()
    turtle.dropDown(16)
    turtle.forward()
    x = x + 1
end

while x > 0 do
    turtle.back()
    x = x - 1
end