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:       My eyes water continuously . Why ?  
 Person2:Perhaps because of the dirty air .  
 Person1:        What is there in the air ?  
 Person2:Some poisonous gas .  
 Person1:        I can't believe that the air in this city is so dirty .  
 Person2:Yes . I think I won't come here again next time .  
 Person1:        So do I .  
 Person2:We waste a vacation .  
 Person1:        Maybe you are right . 

informal