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:       Hi , chary , are you busy this evening ?  
 Person2:sorry , I'm afraid that I've got plans tonight .  
 Person1:        what are you doing ?  
 Person2:I'm going to my parents ' house for my father's birthday .  
 Person1:        how old is he today ?  
 Person2:it's his 50th birthday .  
 Person1:        well , wish him a happy birthday for me .  
 Person2:sure thing . What are your plans for the evening ?  
 Person1:        I was just thinking of going to a movie tonight .  
 Person2:well , if you can wait until tomorrow night , I'll go with you then .  
 Person1:        sorry , I've got people coming over tomorrow night .  
 Person2:sounds like this weekend just isn't going to work out for us .  
 Person1:        sounds that way . Maybe some other time then ?  
 Person2:sure.Hey , I'm sorry , but I've got to get going .  
 Person1:        yeah , me , too . It's about time I made a move .  
 Person2:say hello to your friends for me .  
 Person1:        likewise . See you later .  
 Person2:Bye ! 

formal