In this task you are given a small conversation between two persons and 4 options on how the conversation should continue. Your job is to choose the most reasonable option. The conversation and the options are separated by a newline character. Each dialogue in the conversation are separated by a comma. F and M indicate female and male, respectively.

Ex Input:
M: How much is the cap? ,F: 8 yuan for 1, 14 yuan for 2, and 18 yuan for 3. ,M: Then I'll take 3.
(A) F: 8 yuan, please. (B) F: OK. These four caps cost 18 yuan. (C) F: 14 yuan, please. (D) F: I am afraid I did not quite catch what you were saying. Please repeat it.

Ex Output:
D


Ex Input:
M: Don't worry about your train sickness. I have brought some tablets with me that prevent train sickness. Here, take this one now. I'm sure you'll be alright on the train. ,F: It's very kind of you. By the way where is the dining car? ,M: The dining car is next to the sleeping car. Shall we eat our meals in the dining car? ,F: The attendant will bring some food here. But since the dining car is next to this carriage, we may just as well eat there. ,M: That's alright. How beautiful the scenery is. Look at the vast stretches of green fields. ,F: But it looks lovely only at this time of the year. It's rather dull and lonely in winter. ,M: That's why I prefer to travel in the summer and autumn. ,F: Me, too. I love summer, though it is hot. ,M: The train's pulling in. Do we have time to get offen stretch our legs? ,F: You may go out if you want. The train will stop for 1/4 of an hour before it continues on its way. Whatever you do, don't miss it.
(A) M: Really? The train will stop for 1/2 of an hour before it continues on its way? Oh, I want to give up the travel. (B) M: I didn’t hear you. Please could you tell me again? (C) M: Don't worry. I just want to get off and relax and I will not miss it. (D) M: Really? The train will not stop for 1/4 of an hour before it continues on its way? Oh, I want to stop the train.

Ex Output:
C


Ex Input:
F: We could have flown to Hangzhou, but I prefer traveling on rail. I like very much to watch the beautiful scenery by the window. ,M: I like traveling by train too. I think it had something to my sense of safety.
(A) F: Although traveling by train is not safe, we can enjoy the scenes outside. (B) F: Excuse me, could you repeat the question? (C) F: You are right. We should fly to Hangzhou. I think it's very safe. (D) F: Yes. Traveling by train is very safe. We should go to Hangzhou by train.

Ex Output:

D