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: T he nineteenth of June is my birthday . I'm planning to have a small party . Could you come ?
Person2:Happy birthday to you ! I'd really love to come , but I'm not sure right now . I'll try to make it.Thank you for your invitation .
informal

Person1: Paul , let's go and see Grandpa this afternoon .
Person2:But Grandpa will be working .
Person1: It's Saturday .
Person2:I almost forget .
informal

Person1: I ' Ve decided to go to the cinema alone this evening .
Person2:What has caused you to make such a decision ? Didn ' t you used to go with Helen ?
Person1: Helen is nice but she talks a lot .
Person2:Oh . That ' s really annoying when seeing a film .
Person1: It sure is .
formal