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'll try one of these on . ( The customer tries one of the shoes on . ) It's too big . It slides up and down my heel when I walk around .  
 Person2:Well , let's try a size ten . ( He gets another pair and the customer tries a shoe on ) Looks like a perfect fit .  
 Person1:        Not really . It pinches my toes .  
 Person2:I'm sure they'll be fine once you break them in .  
 Person1:        I don't know ... well , I guess I'll take them , since you don't seem to have anything better .  
 Person2:Thank you , ma'am . It's been a pleasure doing business with you . 

informal