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:       New York Airport.May I help you ?  
 Person2:Yes . I am calling to make sure if flight CG877 will arrive on time ?  
 Person1:        Hold on a moment please ... Sorry , the flight from London has been delayed . It departed two hours later than scheduled.The whether in London was really bad .  
 Person2:You mean it will arrive two hours later than usual ?  
 Person1:        So far we could only deduce this way.If you want further information , would you please call us 1 hour later ?  
 Person2:OK , thank you . 

formal