up

local args = { ... }

numArgs = table.getn(args)

function fuel ()
    if turtle.getFuelLevel() == 0 then
        turtle.select(1)
        turtle.refuel(1)
    end
end

function goodDigUp ()
    while turtle.detectUp() do
        fuel()
        turtle.digUp()
        sleep(0.5)
    end
    fuel()
end

if numArgs > 0.0 then
    height = tonumber(args[1])

    while height > 0 do
        fuel()
        goodDigUp()
        turtle.up()
        height = height-1
    end
end

if numArgs == 2.0 then
    height = tonumber(args[1])

    while height > 0 do
        fuel()
        turtle.down()
        height = height-1
    end
end