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 , miss . I'm Bob . 
 Person2:I'm Amy . How do you do ? 
 Person1:        I'm very glad to meet you . May I have this dance with you ? 
 Person2:Certainly ! I suppose you dance often . 
 Person1:        No , I don't often dance . Isn't this a wonderful party ? 
 Person2:Yes , I'm glad I have come . 
 Person1:        How do you like fox-trot ? 
 Person2:I like it very much . 
 Person1:        You dance beautifully . 
 Person2:Thank you . It's lucky that I have got a good partner . 
 Person1:        Thank you . 

informal