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'.

Ex Input:
Person1: How do you like waltz ?
Person2:It's very nice , I like it very much .
Person1: May I invite you for the first dance ?
Person2:My pleasure . But I'm afraid I'm not much of a dancer .
Person1: In fact , I took up dancing quite recently , too .
Person2:Oh , really ? But you're doing the tango wonderfully well .
Person1: I'm glad you say so , you dance beautifully too . It's lucky that I got a partner .
Person2:Thank you for your compliments . It's just that you are a good leader . Do you like the samba and waltz ?
Person1: Yes . And what dances do you like best ?
Person2:Waltz is my favorite . I like it better than any other dances .
Person1: Oh , the music has stopped . Thank you for the dance .
Person2:My pleasure . Let's go and have a drink .
Person1: Fine .

Ex Output:
informal

Ex Input:
Person1: I work so hard that I do not have the energy to exercise .
Person2:That is just an excuse.You can always find some time to exercise .
Person1: But I work hard all the time for long hours . Often I have no time for lunch . Yet , I am still getting fatter .
Person2:Bill , you know that work is not the same as exercise as it is stressful but not relaxing.And skipping meals will not help you lose weight.In fact your body will only store fat if you miss meals .
Person1: I know you're right , but what can I do ?
Person2:How about going for a walk instead of sitting on the sofa reading the newspaper after dinner every night ?
Person1: But I'll miss the news.It ' s important in my business to keep up with events in China .
Person2:I know , I know.Have you got a portable radio ? You can listen to the news and get healthy at the same time .
Person1: That's a good idea !

Ex Output:
informal

Ex Input:
Person1: Are you have a hand in locking into the case ?
Person2:Yes .
Person1: How do you feel about it ?
Person2:It is really a hard nut to crack . The problem is that the crime was done without leaving any trace .

Ex Output:
formal