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:       So what kind of music turns you on ?  
 Person2:Rock ' n'Roll , I guess .  
 Person1:        You mean the kind of stuff like Nirvana ?  
 Person2:Not really . That ’ s pretty heavy metal . 

formal