Definition: You are given a paragraph, with numbered sentences, and a question. Write the numbers of the sentences needed to answer the given question. Separate multiple sentence numbers with a comma (", "). E.g. "1, 2" would be the correct response if Sent 1 and Sent 2 are needed to answer the given question (do not include sentences that contain no information that is necessary to answer the question). Sort the sentence numbers in an increasing order (i.e., '1, 2', instead of '2, 1'). Your answer should not contain anything than the sentence numbers separated by a comma (e.g. '1, 2, 3, 4'). The given question requires more than one sentence to answer. So, your answer must contain at least one comma (", ").
Input: Paragraph- Sent 1: Allan crouched over his desk once more, pen in hand and mind blank.
Sent 2: He contemplated a story, an outline he had laboriously constructed some time ago.
Sent 3: He had filled his pen and raised it, the nib descending towards the paper, before the sound came: the gentle, persistent tapping of the gnarled, primeval willow touching the window with long, insistent fingers.
Sent 4: His eyes awoke with a passionate, determined flame, though the only light came from the glutted moon.
Sent 5: Allan filled page after page, the words escaping from his mind onto the paper.
Sent 6: Where before they had marched in regiments, practiced in ranks and followed their leaders' commands, the words now escaped in their true forms, unhindered by any stricture.
Sent 7: He continued long into the night, until the eldritch orb had sunk into the waiting hands of the willow, raised perpetually skyward.
Sent 8: Arthur looked up from the results of a night’s frenzied labors and looked Allan in the eye.
Sent 9: "What is this?"Sent 10: he queried, indicating the pages he held in his left hand.
Sent 11: "I decided that… since I wasn't having much success with more – traditional – stories, I might see what sort of work I produced if I let my imagination go freely," Allan replied, somewhat less self-assured than he had been the previous night.
Sent 12: "What in G-d's name could have possessed you to do such a thing," cried Arthur, nearly raising his voice.
Sent 13: "After all I said the day before, why have you abandoned centuries of literary progress for some self-indulgent fantasy?"Sent 14: He shook the papers at Allan, raising them like a belt above the head of a disobedient son.
Sent 15: "This is nothing but a glorified Grimm's tale, a miscarried child of Stoker, a creation less fit to be published than to be told around an open fire at the hovel of some peasant!"Sent 16: He spoke the last word with such heavy intonation that Allan shrank back before the physical wave of sound emanating from Arthur's throat.
Sent 17: "Do you hate the modern system of literature?
Sent 18: Do you personally despise the works the Enlightenment or the progress made since Shakespeare??"Sent 19: For a moment, Allan could hardly do more than shake his head.
Sent 20: "No, of course not… I– " "Then why," Arthur barreled on, "do you disregard them all and return to this superstitious babble, this morbid, paganistic drivel?. 
Question: When Allan fills pages without stricture, how does Arthur react?.
Output:
5, 6, 12.