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 will you spend this lovely weekend ?  
 Person2:I have no idea , any suggestions ?  
 Person1:        We haven't played chess for a long time . How about playing chess ?  
 Person2:It must be fun . But you know , I am not good at chess . I never won since I've learnt to play chess .  
 Person1:        Don ’ t worry , I will teach you how to win .  
 Person2:OK , settled then .  
 Person1:        See you tomorrow .  
 Person2:See you ! 

informal