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:       Why didn't you tell me you had a girlfriend ?  
 Person2:Sorry , I thought you knew .  
 Person1:        But you should have told me you were in love with her .  
 Person2:Didn't I ?  
 Person1:        You know you didn't .  
 Person2:Well , I'm telling you now .  
 Person1:        Yes , but you might have told me before .  
 Person2:I didn't think you'd be interested .  
 Person1:        You can't be serious . How dare you not tell me you were going to marry her ?  
 Person2:Sorry , I didn't think it mattered .  
 Person1:        Oh , you men ! You're all the same . 

informal