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:       Hi , sir . Come and have a look here . We have all kinds of sweaters . 
 Person2:I ’ m looking for a sweater for my wife . Tomorrow is her birthday . And I know she needs a woolen sweater . 
 Person1:        How do you like this grey one ? It ’ s pure wool , one hundred percent of Xinjiang wool . 
 Person2:It feels good . Are there cowl-neck pullovers with the same color ? My wife prefers a turtleneck to a V-shaped collar . 
 Person1:        Yes , we do . What size do you want ? 
 Person2:Size one . By the way , what if I bring home this sweater and my wife doesn ’ t like it ? 
 Person1:        Well , you can always bring it back to us for a full refund . 
 Person2:All right . Could I have it gift-wrapped , please ? 
 Person1:        Yes , just a moment , please . 

informal