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:       What's wrong , Dave ? You look down today . 
 Person2:I didn't pass the English exam . How to learn English well ? Can you give me some suggestions ? 
 Person1:        Well , English is a " paper tiger " . Its natural enemy is adequate practice . 
 Person2:I have done a lot of reading comprehension exercises , and I also spend much time in memorizing English words . 
 Person1:        I suggest you read English texts aloud every day , and try to speak more . That will be beneficial to cultivate your sense of the language . 
 Person2:Really ? I'll have a try . Maybe I will get high marks next time . 

informal