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: I don ' t know why bucks have such a great charm that a great many people are after nothing else .
Person2:They want to be filthy with dough and think it the only source of their happiness .
Person1: But many rich guys don ' t think they are truly happy . There is always some empty feeling deep inside them .
Output:
informal