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'm afraid I have to return this sweater .  
 Person2:May I ask if there's anything wrong with it ?  
 Person1:        You see , there is a run at the neck .  
 Person2:Oh , sorry.But do you want to change it for another one ?  
 Person1:        No , thank you . 

informal