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: Hi , Mike . Haven't seen you for a while . How's Cathy ?
Person2:We are not seeing each other any more .
Person1: What happened ? Did you break up ?
Person2:Yeah . I got sick and tired of her nagging all the time .
Person1: Oh , I am sorry . Maybe you were just emotional at that moment . Do you think you guys can get back together ?
Person2:I don't know . There ' s plenty of fish out there in the sea !
Person1: Oh , you are such a dog !
informal