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:       Which kind of sport do you like to watch ?  
 Person2:Basketball , football , table tennis . I will watch them on TV .  
 Person1:        So you must like NBA game .  
 Person2:Yeah , it is my favorite . Many Chinese people including women and children would like to concern the game . I think they want to see the performance of coming and YiJianLian , the Chinese players in NBA .  
 Person1:        What kind of sport do you like to participate in ?  
 Person2:I am good at tennis and skiing . What about you ?  
 Person1:        I prefer the indoor sports , such as bowling , badminton and squash .  
 Person2:Moderate exercise is really important for health . ' Life lies in movement . '  
 Person1:        How about playing tennis with me ?  
 Person2:Good idea . I will take the racket . 

informal