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:       Do you like flowers ? 
 Person2:Of course , I like flowers . 
 Person1:        What's your favorite flower ? 
 Person2:I like peach blossom , because I like spring . 
 Person1:        Peach blossom is really beautiful . 
 Person2:Yes . How about you ? 
 Person1:        I like lotus . 
 Person2:You have a perfect taste ! 
 Person1:        But there aren't any lotus now . 
 Person2:Yes . It's snowing outside . Let's enjoy the plum blossoms . 
 Person1:        That's not bad . Let's go . 

informal