Satisfying either of these 5-year rules is irrelevant if at the time of the distribution from the Roth IRA you were under age 59½. Otherwise, the distribution from the Roth IRA is a qualified distribution and there is no need to know your contribution basis because a qualified distribution is automatically free of tax an penalty.
Assuming that you were under age 59½ at the time of the distribution from the Roth IRA, your $24,000 of contribution basis in the Roth 401(k) became contribution basis in the Roth IRA. Be sure to click the Continue button on the page that lists the Forms 1099-R that you have entered and, when asked, enter or confirm your Roth IRA contribution basis (including the contribution basis from the Roth 401(k)).
