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:       Good afternoon , Pan Am . May I help you ?  
 Person2:Yes . I'd like to make a reservation to New York for 18th next month .  
 Person1:        Please wait a moment . Let me check for you.The flight is FW 711 and it arrives at 10:00 am .  
 Person2:How long is that journey ?  
 Person1:        14 hours .  
 Person2:Thank you . 

formal