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:       David , what have you been up to lately ?  
 Person2:I went on a trip with my family last week .  
 Person1:        Really ? Where did you go ?  
 Person2:We went to Europe .  
 Person1:        What cities did you go to ?  
 Person2:London , Paris and a few other cities .  
 Person1:        Did you go to Berlin ?  
 Person2:No , We didn't go there . I'd like to go there next time .  
 Person1:        I think this summer is a good time to visit Berlin . It's a beautiful place and the people there are very nice .  
 Person2:That's what I've heard .  
 Person1:        I went there last year . If you want , I can give you some information I have about the city .  
 Person2:Thanks . 

informal