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:       Can you play tennis ? 
 Person2:Yes , I can . 
 Person1:        It is interesting , isn't it ? 
 Person2:Yes , it's very interesting . 
 Person1:        Can you teach me ? 
 Person2:Sure . Take the tennis racket . Now , throw the ball up , and hit it with the racket . Like this . 
 Person1:        Let me try . Oh , I missed ! 
 Person2:Throw the ball up high . 
 Person1:        High ? 
 Person2:Yes , very high . Over your head . Then you will have time to hit the ball . 
 Person1:        Oh ! I hit it . 
 Person2:Well done ! 
 Person1:        Thank you . I think I like playing it . 

informal