to think hard nonstop

Translations
непрерывно напряжённо думать
усиленно думать без остановки
не переставая размышлять
без конца ломать голову
Definitions
To think very intensely and continuously, without taking a break.
To keep pondering a problem or question relentlessly.
Words
to

functional word
чтобы
think

verb
думать
hard

adverb
усердно
nonstop

adverb
без остановки