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'.

Person1: There must be something weighing on your mind . What is it ?
Person2:Dad , I lost mum's necklace . I'm afraid she will scold me .
Person1: Don ' t worry . I'll buy a new necklace as same as the old one .
Person2:It is so kind of you , Dad .
informal

Person1: Mom , can you talk about the philosophy of life with me ?
Person2:You got me on that one .
formal

Person1: What do you think of smoking ?
Person2:It's harmful . Not only for yourself but for others .
Person1: What in your opinion can be done to stop smoking ?
Person2:Stop producing cigarettes .
Person1: But that'll affect the national economy .
Person2:That's right.But I don't think there are better ways .
Person1: How about printing a warning on each cigarette packet ?
Person2:Maybe it can take effect .
formal