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:       What a terrible house !  
 Person2:I'm sick of it , too .  
 Person1:        The door bell doesn't work , there's no hot water , and the building is falling apart .  
 Person2:It's no use complaining . If we had got enough money , we couldn't put up with it , and would have moved out .  
 Person1:        Sure . 

informal