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:       Excuse me , where can I find a guide ? 
 Person2:You can find one at the ticket office . 
 Person1:        Thanks a lot . Have a nice day . 
 Person2:You are welcome . 

informal