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:       I like this shirt.How much is it ?  
 Person2:$ 135 .  
 Person1:        Wow , that's sheer robbery.Shall I make an offer ?  
 Person2:I'm sorry , sir.The price is fixed . 

informal