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:       Nick , it's very nice of you to see me off .  
 Person2:You're welcome . Did you have a good time on this vacation ?  
 Person1:        Very well . If I leave I'll miss you .  
 Person2:Me too . Please write to me as soon as you get Boston .  
 Person1:        I'm sure and I remembered your phone number . I'll call you .  
 Person2:OK , they begin to register .  
 Person1:        It's time I left .  
 Person2:Have a nice journey ! Do give my regards to your parents . 

informal