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 , I would like to buy some business cards .  
 Person2:Excellent . How many would you like ?  
 Person1:        Two thousand would be fine .  
 Person2:You need to fill out this form , please .  
 Person1:        All I want is the same thing on this card .  
 Person2:That will be no problem , sir .  
 Person1:        OK , I'm finished . Here's your form and my old card .  
 Person2:Very good , sir . Your order will be ready in one week .  
 Person1:        Do you think you could finish it in three days ?  
 Person2:No problem , sir . But it will cost you extra . 

informal