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:       I want a doggy bag , waiter . 
 Person2:Sure . How do you like your meal today ? 
 Person1:        Quite good . It was the most wonderful dinner I have ever had . 
 Person2:I am glad you like it . Welcome next time . 

informal