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:       Let's get together this weekend , is that all right ?  
 Person2:Sounds good , when ?  
 Person1:        When is it convenient for you ?  
 Person2:Any time is fine .  
 Person1:        Could you and your wife be ready at nine o'clock ?  
 Person2:Please wait for us even if we're a little late .  
 Person1:        Never mind . I'll be waiting for you .  
 Person2:See you then .  
 Person1:        OK . Bye ! 

informal