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: Consider Input: Person1: It was great meeting you .
Person2:Me too .
Person1: Maybe we can meet again sometime ?
Person2:Of course , but I'll have to go now .

Output: informal

Input: Consider Input: Person1: Song , I hate to say goodbye , but I have to .
Person2:Nice meeting you , Kevin . I hope to see you again .
Person1: Let's keep in touch .
Person2:Sure , let's . Goodbye , then .

Output: informal

Input: Consider Input: Person1: Good afternoon.can I be of any assistance to you ?
Person2:Yes , I am looking for a suit .
Person1: Here are the suits . Which one would you like ?
Person2:Can I have a black one over there ?
Output: formal