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:       Now , David , can I get you a drink ? What will you have ?  
 Person2:Coffee , please .  
 Person1:        What about you , Mary ?  
 Person2:Coke is fine.Thank you . 

formal