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:       Excuse me , can you recommend some places for us to go tonight ?  
 Person2:Since it's your first time to Vienna , I think you should go to the concert .  
 Person1:        Good idea . My wife has a fine ear for music . I am sure she would like it .  
 Person2:Have a nice evening . 

formal