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:       ABC Rent-a-Car . May I help you ?  
 Person2:I would like to rent a car . What kind of car do you have ?  
 Person1:        We have Volkswagen , Pinto , Plymouth and Datsun .  
 Person2:What is the rate ?  
 Person1:        Twenty dollars per day for Volkswagen , Pinto and Datsun , and twenty-seven dollars for Plymouth .  
 Person2:How about mileage and gas ?  
 Person1:        There is no charge for mileage . And fill up the gas when you return the car to us as it is not included .  
 Person2:OK . I'll try a Pinto . I want to rent a car for one week .  
 Person1:        All right , sir . May I have your driver's license ?  
 Person2:Here you are . 

informal