Turtle Stacker

function stacker()
    for i = 4,16 do
        if turtle.getItemCount(i) < 64 then
            for b = 4,16 do
                sel(b)
                if not (b == i) then
                    if turtle.compareTo(i) then
                        turtle.transferTo(i)
                    end
                end
            end
        end
    end
end