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:       Hello , do you know anywhere that sells cheap cashmere sweaters ? 
 Person2:Outlets have cheap cashmere sweaters . 
 Person1:        What a splendid idea ! 
 Person2:Outlets usually give you great deals . 
 Person1:        Thanks for helping me . 
 Person2:You're welcome . 

informal