Definition: 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: Don't just stand outside . Come on in .
Person2:Yeah .
Person1: This is Alex . Remember ? This is Sean .
Person2:Nice to meet you guys .
Person1: Over there are Stacy and Rebecca . We're all on the school's tennis team .
Person2:Who's that guy who's handing out beer to everyone ?
Person1: That's my boyfriend Matt . Isn't he cute ?
Person2:He sure is !
Person1: Come on . I'll introduce you two .
Output:
informal