tl;dr: you don't.
refer to this section of the rc:
Break times may be combined with drain time to meet the above thresholds. For the highest difficulty, this is limited to at most 30 seconds of break time. This does not apply to difficulties with less than 30 seconds of drain time.
therefore, if the song is long enough and you don't have too much break time in your highest diff, it's fine to not have a hard
also, sometimes the way the website calculates drain time is a bit off, so it can't really be taken at face value.