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 , miss . Can I have my dinner please ? I am so hungry .  
 Person2:Sorry , sir . Dinners are available 20 minutes , drinks are served throughout the flight .  
 Person1:        Then please give me a cup of coffee . 

informal