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:       Jane , pleases come with us .  
 Person2:I cannot dance , you know . I have't such a talent .  
 Person1:        Just for fun , not for showing . What do you worry about ?  
 Person2:Nothing . I have told you before that I won't go to the party and that's flat .  
 Person1:        But ... OK . 

formal