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:       Hot in here , isn't it ?  
 Person2:Yeah , really .  
 Person1:        Is it Ok if I sit here ?  
 Person2:Of course . Suit yourself .  
 Person1:        Thanks . My name's Bill Peters , by the way .  
 Person2:Hi , I'm Susan Jackson .  
 Person1:        Nice to meet you . And what do you do , Susan ?  
 Person2:I'm a student at UCLA .  
 Person1:        Oh , are you ? And what are you studying ?  
 Person2:Medicine .  
 Person1:        Really ?  
 Person2:Yes , I want to be a doctor one of these days . What about you ?  
 Person1:        I'm an engineer , I work for Boeing . Say , would you like a drink ?  
 Person2:Sure . Thanks . 

informal