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:       Good coming . room service.What can I do for you ?  
 Person2:I'd like a hamburger and a cup of coffee.My room number is 402 .  
 Person1:        OK.sir . We will bring it to you as soon as possible .  
 Person2:Thank you . 

formal