You are given a conversation between two people. 'Person1:' and 'Person2:' are used to separate their respective dialogues. You are required to assign a label 'formal' if there is an absence of emotion and a presence of questions anywhere within the conversation. If such pattern is not found assign the label 'informal'.

[Q]: Person1: I'm reading an interesting report on Mars .
Person2:Oh , what does it say ? Does it say water could still exist under the surface of Mars ?
Person1: Absolutely ! It says there is water on Mars buried beneath the surface . It's just a matter of how deep it is .
Person2:Then could the soil on Mars somehow be fertile enough to Groh simple plants ?
Person1: The soil would need quite a bit of fertilizer to grow anything . And it would need to be protected from the UV radiation .
Person2:Actually , we are doing a project in school that involves landing a ship and staying on Mars for an extended period of time . Does NASA have any type of portable habitats that could be used to stay on the planet ?
Person1: I'm not sure NASA has built any portable habitats for extended stays on Mars , but they have looked at various designs .
Person2:One of the most exciting things about Mars is that there could have bean life on it . What are your personal opinions on the life on Mars theory ?
Person1: Well , I'm not really an expert in this area , but my understanding is that anything is possible . It's just that it is so hard to determine what went on 4.5 billion years ago .
Person2:But maybe there is a chance of gradually improving the surface and atmosphere of Mars so it may be inhabitable by humans .
Person1: I'm skeptical . Mars is made of rocks containing silicon , iron , and various minerals . It also has an atmosphere of carbon dioxide . It is so different from what we have on earth , you know .
Person2:I'd still like to hope that some day we could set up a human colony there .
Person1: But there are still other big problems we need to solve such as prolonged weightlessness , food storage , and a series of physiological effects .
[A]: formal

[Q]: Person1: Oh , my God ! I've been cheated !
Person2:What ? What did you buy ?
Person1: It's a brick ! I can't believe how stupid I was . Damn it !
Person2:What is it ? Why did you buy a brick ?
Person1: There was a guy on the sidewalk.He had three new boxes , Panasonic video camera boxes.He said he had to get rid of them quick .
Person2:And ?
Person1: So he said he'd sell me one for twenty dollars . A four-hundred-dollar camera for twenty bucks .
Person2:And it's a brick ?
Person1: Yes .
Person2:I can't believe how stupid you are . Why didn't you open the box ?
Person1: I wanted to . But he said , no , the box is still in its plastic wrap from the store.If it's opened , other people won't believe it's new .
Person2:So he had the boxes wrapped in plastic .
Person1: Yes , it was the kind of perfect plastic wrap that comes with new products.Look , it even had a bar-code price sticker on it ! It looked brand new .
Person2:But why would a guy be selling new video cameras for twenty dollars ?
Person1: He said he had to get rid of them . They were stolen .
Person2:Aha ! Now I understand.You were trying to buy stolen goods on the sidewalk.So , what I think is , you deserve to get cheated !
Person1: C'mon , don't blame me ! I thought it was a new camera . We could use it.We were even thinking about buying a camera . I don't understand how he could have such a perfect-looking box .
Person2:That's no problem.He just has a friend who works in a shop that can do plastic wrap . That's easy.And probably it's the same shop he got the boxes from.Maybe his friend works in an electronics store . They sell video cameras there.Probably they had a couple video camera boxes lying around.So they get the idea of wrapping bricks to sell to fools like you.Twenty dollars a brick . That's a good profit if they can sell enough bricks .
Person1: You're right , Sarah . I was a fool . I can't believe it . How could I fall for such a trick ?
[A]: informal

[Q]: Person1: Mr.Keller , may I call at your home sometime the week ?
Person2:Oh , certainly.When would you like to come ?
Person1: Well , when will it be convenient for you ?
Person2:This weekend would be OK with me .
[A]:
formal