Given the task definition and input, reply with output. 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'.

Person1: Room service . May I come in ?
Person2:Come in please .
Person1: Mr . Green ?
Person2:Yes . Put them on there please .
Person1: OK.If you need anything , just call the Room service .
Person2:Thank you . By the way , what shall we do with the plates when we finish our meal ?
Person1: Just leave them outside the door . We will take care of it .
Person2:I see . Thanks a lot .
formal