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:       Hello , my name is Bill Martin and we have a reservation for party tonight .  
 Person2:Yes , what can I do for you ?  
 Person1:        I need to cancel that . We have had a last minute change of plans .  
 Person2:I see . Would you like me to reschedule you for another night ?  
 Person1:        OK , we will let you know as early as possible . By the way , will we be able to get a refund on this cancellation ?  
 Person2:Certainly .  
 Person1:        Thank you very much .  
 Person2:That's all right . I hope we can help you at some other time . Good-bye .  
 Person1:        Good-bye . 

informal