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'.

Example Input: Person1: Hi , Zhengjun , what make you so happy .
Person2:You know what , I've just got a new job with a computer company .
Person1: Oh , congratulations !
Example Output: informal

Example Input: Person1: Hello !
Person2:Is that the box-office ?
Person1: Yes .
Person2:I'd like to book two tickets for the film ' Jane Eyre ' for this evening , please .
Person1: Just a minute please . Oh , I'm sorry , all the tickets for tonight have been sold out .
Person2:What a pity ! How about tomorrow evening ?
Person1: Oh , you're lucky , there are just two tickets left . Do you want to take them ?
Person2:Wonderful , I'll take them .
Person1: OK , your name and telephone number please .
Person2:Wang Min . Telephone number is 13811658 . Can I pick the tickets this afternoon ?
Person1: Yes , of course .
Person2:Thank you very much .
Example Output: informal

Example Input: Person1: Excuse me , where is the Beijing Railway Station ?
Person2:You can take the subway to get there .
Person1: How long will it take to get there ?
Person2:It takes only ten minutes .
Person1: May I take a bus or a taxi to get there ?
Person2:You can take No . I bus or a taxi .
Person1: Excuse me , sir . Where is the No . 1 bus stop ?
Person2:Please turn right at the traffic lights .
Person1: Thank you very much .
Example Output:
informal