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:       Why don't you come round for a meal one evening next week ?  
 Person2:I'd love to .  
 Person1:        Which day would suit you ?  
 Person2:Any day except Tuesday .  
 Person1:        How about Thursday ?  
 Person2:Yes , Thursday would be fine . What time shall I come ?  
 Person1:        Oh , about 6:00 . Will that be OK ?  
 Person2:Yes , of course . Thank you very much .  
 Person1:        See you on Thursday , then . 

informal