Detailed 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'.
Problem: Person1: You look tired . Did you sleep well last night ?
Person2:I stayed up all night writing a report .
Person1: Go easy . Overwork is bad for your health .
Solution:
formal