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:       Let me see . How much should I pay for you ? 
 Person2:Don ’ t think about it ! 
 Person1:        No , this will not do . Let me see . 
 Person2:You pay for the taxi and dinner , then to even things up . 
 Person1:        Good ideas . 

informal