placestone

local slot = 3

function checkstock()
turtle.select(slot)
return turtle.getItemCount(slot)
end

local stock = checkstock()

function nextslot()
    if slot < 8 then
        slot = slot + 1
    elseif slot == 8 then
        slot = 3
    end
end

if stock == 0 then
    while stock == 0 do
    nextslot()
    stock = checkstock()
    end
end
print(stock)

turtle.forward()
turtle.placeDown()