try

turtle.select(1)

textutils.slowWrite("\n")
textutils.slowWrite("loading... \n")

textutils.slowWrite("refueling... \n")

fuellevel=turtle.getFuelLevel()
turtle.refuel()
if fuellevel==turtle.getFuelLevel() then
    textutils.slowWrite("Warning: no fuel added! \n\n")
end

textutils.slowWrite("ask questions... \n")
textutils.slowWrite("what length do you want to dig? \n")
lengthdig = tonumber(read())
textutils.slowWrite("how deep do you want to dig? \n")
deepdig = tonumber(read())

textutils.slowWrite("starting... \n")

length = 1
deep = 0

print("Deep: "..deep.."/"..deepdig)
print("Length: "..length.."/"..lengthdig)

while true do

if deep~=deepdig then
    turtle.digDown()
    turtle.down()
    turtle.turnLeft()
    turtle.dig()
    turtle.turnRight()
    turtle.turnRight()
    turtle.dig()
    turtle.turnLeft()
    deep = deep+1
    print("Deep: "..deep.."/"..deepdig)
else
    print("Length: "..length.."/"..lengthdig)
    if length==lengthdig then
        finish()
    else
        turtlegoup = 0
        while turtlegoup ~= deepdig do
            turtle.up()
            turtlegoup = turtlegoup + 1
        end
        deep = 0
        length = length+1
        turtle.forward()
    end
end

end

function finish()

textutils.slowWrite("\n")
textutils.slowWrite("Finished! \n")
textutils.slowWrite("\n")

end