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:       Do I need a visa ?  
 Person2:No , I shouldn ’ t think so . But you must take your passport of course .  
 Person1:        Yes , I know . I must get my traveler ’ s check and some foreign currency .  
 Person2:Yes , you need the traveler ’ s check but you needn ’ t get any foreign currency . You can have my US Dollars , I don ’ t need them .  
 Person1:        Really ? That ’ s very good of you , Helen . But I must get a new suitcase , my old one needs repairing .  
 Person2:You needn ’ t buy one . You can have mine .  
 Person1:        That ’ s very kind of you , Helen . I hope you don ’ t mind my leaving you like this . I need a holiday . It won ’ t be long .  
 Person2:Don ’ t be silly , John . I ’ m going with you . It ’ s necessary for me to have a holiday too . 

informal