local tUp = false
local tDown = false
local tFront = false


while true do
    tUp = false
    tDown = false
    tFront = false

	if turtle.detectUp(Sand) then
		while turtle.detectUp(Sand) do
			turtle.digUp()
			tUp = true;
		end
	elseif turtle.detectDown(Sand) then
		while turtle.detectDown(Sand) do
			turtle.digDown()
			tDown = true;
		end
	elseif turtle.detect(Sand) then
		while turtle.detect(Sand) do
			turtle.dig()
			tFront = true;
		end
	end

    if tUp == true then
        turtle.up()
    elseif tDown == true then
        turle.down()
    elseif tFront == true then
        turtle.forward()
    else
        turtle.turnLeft()
    end

end