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:       Hi , I'm here to check in .  
 Person2:Would you please fill out this registration 1 form ?  
 Person1:        Thank you ... Excuse me , sir . You forgot to fill in your visa number .  
 Person2:Did I ? Let me see that ... Oh , sorry ... here you are . 

informal