input question: W: I'll have to check. Can I help you with anything else? M: I'd like a 20-cent stamp, please. W: There you are. What was said before this conversation????
output answer: M: How much is an airmail letter to Japan?

input question: M: Oh, there was something wrong with my mobile. I will have to buy a new one. What was said before this conversation????
output answer: W: I dialed your phone number many times yesterday, but I couldn't get through. What's the matter?

input question: M: I think so. What was said before this conversation????
output answer: W: It's a wonderful trip.

input question: M: No, I just have a glass of milk. What about you? W: I have a big breakfast. I eat eggs and toast, and I drink milk. What was said before this conversation????
output answer:
W: Do you eat a big breakfast?