local moves = {}

local cont = true
local digSuccess

while cont do
   if turtle.detectDown() == true then
       digSuccess = turtle.digDown()
   end

    if digSuccess == true or turtle.detectDown() == false then
        local moveSuccess = turtle.down()
        if moveSuccess == true then
            moves[table.getn(moves)] = "down"
        else
            cont = false
        end
    end
end

local i = 0

while i < table.getn(moves) do
    turtle.up()
    i = i + 1
end