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'.
Q: Person1: Sorry , I have to rush off and catch the 9 o'clock train to Paris .
Person2:Then you must hurry up.There ' s only ten minutes left .
Person1: Until we meet again .
A:
informal