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:       I went to Jessie's birthday party yesterday . It was very good . 
 Person2:I didn't know about it . What did you do ? 
 Person1:        We ate a lot of things . We played games and gave gifts to Jessie . We had a lot of fun . 
 Person2:You were really lucky . 
 Person1:        My birthday comes next month . I want to hold a birthday party , too . 
 Person2:I hope I can go to your party . 

informal