local function pullStone(slot)
    turtle.select(slot)
    while not turtle.suckDown(1) do
        sleep(0.5)
    end
end

while true do
    pullStone(1) -- top-left
    pullStone(2) -- top-right
    pullStone(5) -- bottom-left
    pullStone(6) -- bottom-right

    turtle.craft()
    turtle.dropUp()
end