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:       OK , Hello ! 
 Person2:Hello ! 
 Person1:        Hi , what's your name ? 
 Person2:Yeah , my name is Nandu . 
 Person1:        Nandu . Nandu , how do you spell you name ? 
 Person2:Yeah , my name is like N-A-N-J-U . 
 Person1:        Oh , OK . That's a nice name , Nandu . And where are you from ? 
 Person2:I'm from Madras . 

formal