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:       Mr . Lin , what are you interested in ? 
 Person2:I enjoy camping . 
 Person1:        Really ? I'm not much of an outdoor person . What do you like about it ? 
 Person2:I love the fresh air , the scenery the exercise , and the time to think . 
 Person1:        Do you hike or fish on your trips ? 
 Person2:Yes , both . Last trip I fished a little and hiked five miles . 
 Person1:        Did you catch anything ? 
 Person2:Yes , but I threw them back . 
 Person1:        How about Joining our summer camp next week ? 
 Person2:Great ! I can't wait . 

informal