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:       Okay , I ’ ll take it . By the way , do you have delivery service ?  
 Person2:You don ’ t need to carry the furniture home because we have delivery service .  
 Person1:        Do you charge for delivery ?  
 Person2:Wo will deliver the goods to you for free .  
 Person1:        Very good . Could you deliver it to this address ?  
 Person2:Sure . Please write down your name and your phone number .  
 Person1:        OK . Can you tell me the delivery time ?  
 Person2:No later than tomorrow .  
 Person1:        Thanks . 

informal