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:       Tom , I've got good news for you .  
 Person2:What is it ?  
 Person1:        Haven't you heard that your novel has won The Nobel Prize ?  
 Person2:Really ? I can't believe it . It's like a dream come true . I never expected that I would win The Nobel Prize !  
 Person1:        You did a good job . I'm extremely proud of you .  
 Person2:Thanks for the compliment .  
 Person1:        You certainly deserve it . Let's celebrate ! 

informal