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:       I think it's about time that we had to go .  
 Person2:What ? Won't you have more drinks ?  
 Person1:        I'd love to , but I have to get up early tomorrow and get to the office on time .  
 Person2:Oh ! I'm sorry , but I wish you could stay .  
 Person1:        Thank you for a very enjoyable evening and your hospitality .  
 Person2:Don't mention it . You can come whenever You are free . 

informal