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 morning , Mary !  
 Person2:Good morning , John !  
 Person1:        I want to have a few friends over for a dinner party to celebrate my birthday . Would you be able to come the next weekend on Saturday ?  
 Person2:I'd be delighted to , John . Saturday did you say ?  
 Person1:        Yes , if that's all right for you .  
 Person2:I'm pretty sure I'll be all right . In fact , I'd be delighted to come over and celebrate your birthday with you.What time are you planning to start ?  
 Person1:        Oh , good . If you could come around six thirty or seven o'clock , that would give us some time to chat a whit over a glass of wine before dinner .  
 Person2:That sounds fine . I'll be there around seven . 

informal