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:       May I help you ?  
 Person2:This dress is beautiful . May I try it on ?  
 Person1:        I'm afraid you can't .  
 Person2:What is the material of this dress ?  
 Person1:        It's 100 % cotton .  
 Person2:That's good . Can you give me a reduction ?  
 Person1:        It's already reduced 20 % .  
 Person2:Do you have any cheaper ones ?  
 Person1:        Yes . Please come this way . 

informal