In an exercise I see:
Если вы не сделаете домашнее задание, вы об этом жестоко пожалеете.
That I translate: If you don't do your home work, you will regret it deeply.
But жестоко is in the dictionary as "with cruelty; with violence" and so. Perhaps my translation is not the better.
Will you help me ? Tks