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:       Guess what ? Paul and Susan are engaged .  
 Person2:Really ? When did that happen ?  
 Person1:        A week ago ? They met last summer and now just sink . They will be married soon .  
 Person2:Have they set a date for the wedding ?  
 Person1:        No , not yet . But Susan says they ’ d like to get married in November or December . Then they ’ ll go to Hawaii for their honeymoon . 

informal