--http://pastebin.com/FYV6bmu3


local howmany = {...}

local function toBedrock(num)
    local howmany = tonumber(num)
    local startY = 0
    local completed = 0
    local notBedrock = true

    local function returnToSurface()
        while startY < 0 do
            if turtle.getFuelLevel() == 0 then
                    turtle.refuel(1)
            end
            turtle.up()
            startY = startY + 1
            print(startY)
        end
    end

    local function digToBedrock()
        while notBedrock do
            if turtle.getFuelLevel() == 0 then
                    turtle.refuel(1)
            end
            turtle.digDown()
            notBedrock = turtle.down()
            print(startY)
            if not notBedrock then
                returnToSurface()
                break
            else
                startY = startY - 1
            end
        end
    end

    while completed < howmany do
        digToBedrock()
        turtle.dig()
        turtle.forward()
        completed = completed + 1
        notBedrock = true
    end
end

toBedrock(howmany[1])

-- local startY = 0
-- local completed = 0
-- local notBedrock = true

-- local function returnToSurface()
--     while startY < 0 do
--         if turtle.getFuelLevel() == 0 then
--                 turtle.refuel(1)
--         end
--         turtle.up()
--         startY = startY + 1
--         print(startY)
--     end
-- end

-- local function digToBedrock()
--     while notBedrock do
--         if turtle.getFuelLevel() == 0 then
--                 turtle.refuel(1)
--         end
--         turtle.digDown()
--         notBedrock = turtle.down()
--         print(startY)
--         if not notBedrock then
--             returnToSurface()
--             break
--         else
--             startY = startY - 1
--         end
--     end
-- end

-- while completed < tonumber(howmany[1]) do
--     digToBedrock()
--     turtle.dig()
--     turtle.forward()
--     completed = completed + 1
--     notBedrock = true
-- end

-- digToBedrock()