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'.

Input: Consider Input: Person1: Our philosophy teacher is very humorous .
Person2:I usually have the wrong notion that he's very serious .
Person1: No , not at all.The examples he gives are very interesting .
Person2:No wonder when I pass your room , I always hear your laughter .

Output: informal

Input: Consider Input: Person1: What did he say ?
Person2:He said he would tell us the secret of becoming a successful man .
Person1: It ' s too good to be true ! If I were there , I would ask him if he himself was a successful man .
Person2:Nobody would drive him up a wall by asking him such a question , you know .

Output: formal

Input: Consider Input: Person1: I guess you should know that you need to be hospitalized .
Person2:Of course I know .
Person1: Now you can go to the in-patient department to go through the admission procedures .
Person2:OK . I'll go right now . By the way , do you think I ' ll have to stay in the hospital for long ?
Person1: It's hard to say . It depends on your recovery condition . But you need to stay for at least one day for observation .
Person2:Thank you , Doctor . I will go now . Bye-bye .
Person1: Bye !
Output: formal