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:       I must admit I'm not at all interested in math .  
 Person2:I'm sure you'll soon begin to like it.It ' s such an interesting subject .  
 Person1:        But I don't think I'll ever show my liking to math . 

informal