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:       How do you like other films starring Charlie Chaplin ?  
 Person2:Well , I like others very much , but I really don't think much of this one .  
 Person1:        You don't like the performance , do you ?  
 Person2:Yes , but I don't like the story . 

formal