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: David , I ' m going to China .
Person2:Really ? How do you get the chance ?
Person1: You know . I took part in the Chinese contest . I was the best and they gave me this reward . I don ' t have to pay for my trip .
Person2:Congratulations . How lucky you are !
Person1: Thank you . I ' m leaving tomorrow morning .
Person2:I ' m sure you ' ll enjoy the trip . China is such a beautiful country .
Person1: I ' m sure I will .
Person2:Have a nice journey , Lily .
Person1: Thank you , David .

Ex Output:
informal

Ex Input:
Person1: T he nineteenth of June is my birthday . I'm planning to have a small party . Could you come ?
Person2:Happy birthday to you ! I'd really love to come , but I'm not sure right now . I'll try to make it.Thank you for your invitation .

Ex Output:
informal

Ex Input:
Person1: The National Day is coming . What are you going to do during the holiday ?
Person2:I have no idea .
Person1: Why don't you go sightseeing ?
Person2:It isn't a good time because there must be many tourists in the scenic spots . What about your plans ?
Person1: I intend to stay at home for the whole seven days and have a good rest .

Ex Output:
formal