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:       Who did the stupid thing ? 
 Person2:Maybe it was Dick . 
 Person1:        I don't think so . Dick has been on the ball and he never does things like that . 
 Person2:Then it must be a naughty boy who did it . 

formal