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:       Hi , Lucy ! 
 Person2:Hi.It ' s a wonderful wedding , isn't it ? 
 Person1:        Yes , It's very great . 
 Person2:Mary's father is a rich man , isn't he ? 
 Person1:        You are right , Mary's father is responsible for the entire wedding-arrangement , costs , etc . I think he must spend much money . 
 Person2:Will Mary and her husband be ready to leave for their honeymoon ? 
 Person1:        Yes.Look ! Mary is going to throw the bride bouquet . 
 Person2:Oh , I'll try to catch it . 

informal