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:       My mother likes to split hairs .  
 Person2:What do you mean by that ?  
 Person1:        She has keen to buy something which is much cheaper .  
 Person2:Mothers like that . 

formal