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:       Would you like a cup of coffee ?  
 Person2:Yes . That would be good .  
 Person1:        Oh , no .  
 Person2:What's the matter ?  
 Person1:        This machine is out of order .  
 Person2:You shouldn't have used the machine . Did you lose your money ?  
 Person1:        I sure did .  
 Person2:You ought to complain . These machine are always out of order . 

formal