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:No , thank you . I'm just looking . Maybe later I might need your help . 
 Person1:        I hope you will ! Take your time . We have a lot more upstairs . 
 Person2:Oh , you do ? You certainly have a large selection . 

informal