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: 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 .
Example Output: informal

Example Input: Person1: Where's your better half ?
Person2:She's at home .
Example Output: formal

Example Input: Person1: I heard you received a prize for you book .
Person2:yes , I did . I won a prize for best local history book at the annual book awards .
Person1: congratulations ! You must be very proud of your achievement .
Person2:actually , I was happy just to get the book published . Winning the prize was an added bonus .
Person1: what was the prize ?
Person2:I won $ 200 to spend on any books of my choice .
Person1: that ' s a great prize for a person who writes books ! Have you ever won a prize before ?
Person2:I shared a prize with some friends last week . We won a bottle of whisky at a pub quiz .
Person1: I won $ 10 in the lottery last month . Perhaps next time , I ' ll be luckier and win the jackpot !
Example Output:
informal