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:       What is your favorite coffee ?  
 Person2:Irish coffee is my favorite . But I'm not particular on it .  
 Person1:        All right . Would you make coffee yourself when you are at home ?  
 Person2:Not very often . Making coffee is a bit troublesome . Most of the time , I just buy takeout at Starbucks . And also , I quite like instant coffee .  
 Person1:        I think instant coffee is becoming more and more popular . Though its taste is not perfect , it's really cheap and convenient .  
 Person2:Exactly . Nescafe is the world's favorite coffee . People love it all over the world .  
 Person1:        I agree . I heard that in the western countries , almost everyone likes coffee . Is that true ?  
 Person2:Yes . No doubt about that . For us , coffee is more a living style rather than a simple drink . I heard Chinese people don't drink that much coffee .  
 Person1:        No , we don't , especially the elder people . But more and more young people fall for coffee nowadays .  
 Person2:I suppose so . That's probably why there are so many wonderful coffee houses in China now . 

formal