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:       Would you like to go skating with me this afternoon ? 
 Person2:Oh , I'd love to . But we're going to clean our dormitory . I can't be absent . 
 Person1:        Maybe another time . People say that boys ' dormitories are in a mess , is it true ? 
 Person2:In fact , our dormitory is much worse than they can be described . 
 Person1:        It's hard for me to imagine . How can you stand that ? 
 Person2:You'll get used to it gradually . 
 Person1:        Oh my God , don't you know that such living environment is not healthy ? 
 Person2:Yes , we do . That's why we have a cleaning every three months . 
 Person1:        Three months ? Incredible ! 

informal