Instructions: 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'.
Input: Person1: I've brought some potato chips . Would you like some , Jack ?
Person2:Yes . I'd like to swap some of my peanuts for your chips .
Person1: That'll be fine . Thanks .
Person2:Do you have any ketchup ?
Person1: I forgot to bring it , but maybe Mary has some . Let's go and ask her .
Output:
informal