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:       Would you like to stretch your legs ?  
 Person2:Sure .  
 Person1:        Let's get a soft drink .  
 Person2:Do we have enough time ?  
 Person1:        It's a fifteen-minute intermission .  
 Person2:The seats are excellent . We're right in the center .  
 Person1:        It's a new concert hall and the acoustics are great .  
 Person2:I can't agree more .  
 Person1:        Is this your first time to come to a symphony concert ?  
 Person2:In the United States , yes . But back in China , I went to concerts a couple of times with my parents .  
 Person1:        Do you have large concert halls in your city ?  
 Person2:We have two . One is like this one . The other is a little smaller .  
 Person1:        That's great . Well , we'd better get back to our seats . It's about to start . 

informal