Definition: 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: Person1: There was something wrong with the plane last Thursday .
Person2:Which flight ?
Person1: Flight 198 . Fortunately , there were few passengers .
Person2:How about the passengers ?
Person1: Well , all the passengers and crew members landed on their feet finally .
Output:
formal