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:       Housekeeping , may I come in ?  
 Person2:Come in please .  
 Person1:        Good coming , sir . May I do your room now ?  
 Person2:How long will it take ?  
 Person1:        Your room will be ready in half an hour .  
 Person2:Well , would you please come back fifteen minutes later ? We are to visit the Tower .  
 Person1:        Of course , sir . Have a good day . 

formal