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 (", ").

Ex Input:
Paragraph- Sent 1: (CNN) -- In November 2009, Norwegian freelance journalist Paul Refsdal is riding in a pick-up truck on a dusty track of Afghan road.
Sent 2: The Taliban have kidnapped him.
Sent 3: If the truck turns right, he knows he's being sold to another militant group.
Sent 4: A left turn means his kidnappers have decided to let him go.
Sent 5: His journey started when Refsdal, who wanted to document the daily lives of the Taliban, accepted the invitation of a Taliban commander to film him and his fighters.
Sent 6: Refsdal later accompanied another Taliban commander, Omar, to his hideout on a second embed.
Sent 7: As part of CNN's "Taliban" documentary, Refsdal talked with CNN's Anderson Cooper about going from invited guest to kidnap victim -- a harrowing experience that began the way it later ended, with Refsdal in a truck.
Sent 8: Here is an edited excerpt: REFSDAL: We rent a pickup truck and we drive into this valley that doesn't really have a road.
Sent 9: I'm told it is not possible to drive anymore.
Sent 10: We will have to walk for several hours up the hillside to one village, and we have to sneak a little bit.
Sent 11: Omar is very particular about I should cover my face.
Sent 12: I assume this is because they don't want informers to see that there's a foreigner coming.
Sent 13: And we sleep in a house, and everything seems OK. Then, the next day we are asked to go to another house, just 100 meters down the hillside.
Sent 14: We have to wait there, because they're going to have a meeting.
Sent 15: After a couple hours, one of the fighters comes and says he's from al Qaeda.
Sent 16: And he says that he has information that I was spying for the coalition, so both my translator and I will be executed tonight.
Sent 17: And he goes on, saying that we're going to be killed with a knife.
Sent 18: ... He explains how much he hates foreigners and he wants to eat the flesh of foreigners.
Question: What happened to Paul Refsdal in November 2009.

Ex Output:
1, 2.

Ex Input:
Paragraph- Sent 1: Feel the top of your desk.
Sent 2: Does it look and feel smooth?
Sent 3: Yes, it feels and looks smooth, but is it really?
Sent 4: Even when surfaces look smooth to the unaided eye, they may not be.
Sent 5: Scientists use a microscope to look at things more closely.
Sent 6: Through a microscope, smooth surfaces may appear rough or bumpy.
Sent 7: Look at the metal surfaces in Figure 1.8.
Sent 8: The metal foil is so smooth that it is shiny.
Sent 9: However, when highly magnified, it is clearly not smooth.
Sent 10: It actually looks to be very bumpy.
Sent 11: All those bumps grab the bumps of other surfaces.
Sent 12: They grind together.
Sent 13: They oppose the motion of the two surfaces.
Sent 14: Now you know what causes friction.
Question: What is it called when the motion of two surfaces together is opposed?.

Ex Output:
13, 14.

Ex Input:
Paragraph- Sent 1: American Airlines Flight 11: FAA Awareness.
Sent 2: Although the Boston Center air traffic controller realized at an early stage that there was something wrong with American 11, he did not immediately interpret the plane's failure to respond as a sign that it had been hijacked.
Sent 3: At 8:14, when the flight failed to heed his instruction to climb to 35,000 feet, the controller repeatedly tried to raise the flight.
Sent 4: He reached out to the pilot on the emergency frequency.
Sent 5: Though there was no response, he kept trying to contact the aircraft.
Sent 6: At 8:21, American 11 turned off its transponder, immediately degrading the information available about the aircraft.
Sent 7: The controller told his supervisor that he thought something was seriously wrong with the plane, although neither suspected a hijacking.
Sent 8: The supervisor instructed the controller to follow standard procedures for handling a "no radio" aircraft.
Sent 9: The controller checked to see if American Airlines could establish communication with American 11.
Sent 10: He became even more concerned as its route changed, moving into another sector's airspace.
Sent 11: Controllers immediately began to move aircraft out of its path, and asked other aircraft in the vicinity to look for American 11.
Sent 12: At 8:24:38, the following transmission came from American 11: American 11: We have some planes.
Sent 13: Just stay quiet, and you'll be okay.
Sent 14: We are returning to the airport.
Sent 15: The controller only heard something unintelligible; he did not hear the specific words "we have some planes."Sent 16: The next transmission came seconds later: American 11: Nobody move.
Sent 17: Everything will be okay.
Sent 18: If you try to make any moves, you'll endanger yourself and the airplane.
Question: What were the first things done by America 11 that led the air traffic controller to notify his supervisor that something was wrong with the flight?.

Ex Output:
2, 3, 5, 6.