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:       John's father got married again .  
 Person2:Married whom ?  
 Person1:        If I tell you . , you must be completely taken aback .  
 Person2:Come on . Tell me what happened .  
 Person1:        He married a girl who is only eighteen !  
 Person2:Is that true ? But anyhow , it's none of our business , isn't it ? 

informal