Instructions: 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: As we know , mobile phones bring people great convenience and shorten the distance among friends and relatives .
Person2:It bears a great many of advantages , but also some weak points .
Person1: Is it ? I've never thought of any disadvantages of the mobile phone .
Person2:For instance , the mobile phone seriously distracts the attention of people from work and study .
Person1: That's true . Some people pay too much attention to their mobile phones .
Person2:Actually , it's not the fault of the mobile phone . But people should have a proper attitude towards it . Mobile phone is a tool serving people , not the fetters restricting them .
Output:
formal