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:       Hey , Robert , what are you doing this weekend ?  
 Person2:I didn't have any big plans .  
 Person1:        We are putting together a birthday party for Mary .  
 Person2:That sounds like fun . Where will it be ?  
 Person1:        We thought it would be fun to have a pool party at Jay's house .  
 Person2:Oh good ! Can I bring anything ?  
 Person1:        We will be providing hot dogs , hamburgers , and cake , but people can bring side dishes .  
 Person2:I am assuming that the dress is casual .  
 Person1:        Dress casually and bring your bathing suit !  
 Person2:Wonderful . Just e-mail me the time and date and I'll be there . 

informal