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:       Do you want black or white coffee ?  
 Person2:White , please  
 Person1:        Look ! there's a Folk concert tomorrow evening . Do you Want to go ?  
 Person2:I don't like Folk music very much .  
 Person1:        What kind of music do you like ?  
 Person2:I like classical music . Do you ?  
 Person1:        Not very much . Classical music sends me to sleep  
 Person2:I don't believe you .  
 Person1:        It ’ s true .  
 Person2:You are funny !  
 Person1:        So are you ! How about another coffee ? 

formal