Valmiki Ramayana Kishkindha Kanda Sarga 59 Shloka 27
Original Shlokaकामं खलु दशग्रीव स्तेजोबलसमन्वितः।।4.59.27।। भवतां तु समर्थानां न किञ्चिदपि दुष्करम्।
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दशग्रीवः the tenheaded Ravana, तेजोबलसमन्वितः खलु कामम् is mighty, powerful and strong, तु but, समर्थानाम् for the efficient ones, भवताम् for you, दुष्करम् difficult, किञ्चिदपि even a little, न not.
'The tenheaded Ravana is mighty, powerful and strong, indeed. But you are efficient and it will not be difficult for you to achieve this task.