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 really like the record you lent me the other day .  
 Person2:I'm glad you like it .  
 Person1:        And thank you very much for letting me keep it so long .  
 Person2:Not at all .  
 Person1:        I'm most grateful . Everyone in our class enjoyed it .  
 Person2:I'm glad .  
 Person1:        Would you mind my keeping it for another week ? 

informal