Given the task definition, example input & output, solve the new input case.
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'.
Example: Person1:      Hey man , you wanna buy some weed ?  
 Person2:Some what ?  
 Person 1:Weed ! You know ? Pot , Ganja , Mary Jane some chronic !  
 Person2: Oh , umm , no thanks . 
 Person1:      I also have blow if you prefer to do a few lines . 
 Person2: No , I am ok , really . 
 Person1:      Come on man ! I even got dope and acid ! Try some ! 
 Person2: Do you really have all of these drugs ? Where do you get them from ? 
 Person1:      I got my connections ! Just tell me what you want and I ’ ll even give you one ounce for free . 
 Person2: Sounds good ! Let ’ s see , I want . 
 Person1:      Yeah ?  
 Person2:I want you to put your hands behind your head ! You are under arrest ! 
Output: informal
Based on the conversation, we can see that there is a presence of exclamation which is not present in a formal discussion. Therefore this is an informal conversation

New input case for you:  Person1:       Excuse me . Can you tell me how to find some books on social science ?  
 Person2:Sure . You see all these little drawers here and all the way around the walls ?  
 Person1:        Yes .  
 Person2:These drawers contain cards describing every book in our library . Together they constitute the library's " card catalog " . You can see that each drawer runs from one part of the alphabet to another . Fox example , this drawer goes from SCA to SCM .  
 Person1:        So if I'm looking for a look called A History of Western Society , I'd just look under ' A ' .  
 Person2:No . You'd look under ' W ' . The articles ' a ' and ' the ' don't count in our alphabetization , and cards are generally omitted for extremely common words and phrases such as ' history of ' , ' introduction to ' , ' story of ' and so forth .  
 Person1:        What if I don't know the title of the book ?  
 Person2:Well , you can look under the author's name .  
 Person1:        Could you give me an example ?  
 Person2:Suppose you want to find a book by your professor , William Smith . You'd look under SMITH and then WILLIAM . Since that's very common name , you may have to go through several ' William Smith ' until you come to the one who wrote book on the subject you are interested in . 
Output:
formal