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:       Linda , John and I are going to get married next week . 
 Person2:That's wonderful . Congratulations . 
 Person1:        Thank you , Linda . We would love you to come to our wedding . 
 Person2:I'd love to . What date is it ? 
 Person1:        It's May 1st . 
 Person2:What day is that ? 
 Person1:        It's Saturday . Could you make the time ? 
 Person2:Yes , sure . What time will the wedding begin ? 
 Person1:        At nine sharp . 
 Person2:Very good ! I'm looking forward to it . Please give my best regards to John . And I wish you best luck ! 
 Person1:        Thanks . 

informal