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:       How happy you are ! Next Monday is your wedding day . Congratulations ! 
 Person2:Thank you ! 
 Person1:        Fred is really a good guy . And he loves you so much . 
 Person2:Yeah . I'm lucky to be his wife . 
 Person1:        He's after your own heart , it is important . 
 Person2:So he will make a perfect husband . Make sure you will be here next Monday . 
 Person1:        I promise ! 

informal