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:       Can I help you ?  
 Person2:Yes , I'd like to have a look at the 2 - piece suit .  
 Person1:        What size do you wear ?  
 Person2:Middle size  
 Person1:        Then please look at this suit .  
 Person2:Does this suit come in other color ?  
 Person1:        Yes , we have some in blue , green , black and brown .  
 Person2:How much is the brown one ?  
 Person1:        US $ 138 .  
 Person2:Then I'll take it . 

informal