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:       Plaza Hotel , good morning . Leo speaking . 
 Person2:Ah yes , I'd like to book two rooms for myself and my father . Could you tell me the cost of a single room per night ? 
 Person1:        Certainly . A single room is 120 dollars American , per night . 
 Person2:Fine . 
 Person1:        And when would you like the rooms ? 
 Person2:From the 25th to the 28tri of September . 
 Person1:        Arriving the 25th of September and leaving on the 28th ? Three nights ? 
 Person2:That's right . 
 Person1:        Just a minute please . 
 Person2:Yes , we have rooms available then . You require two single rooms ? 
 Person1:        Yes , thank you . 
 Person2:Can l have your name please ? 
 Person1:        My name is Mona White . 
 Person2:And your father's name , Ms White ? 
 Person1:        Jack Webber . 
 Person2:Could you spell the surname please ? 
 Person1:        Sure . W-E-double B-E-R . 
 Person2:Double P for Papa ? 
 Person1:        No , double B for Bravo 

formal