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:       Would you like to go to the theater with me tomorrow ?  
 Person2:Yes , of course . Have you got the tickets ?  
 Person1:        That's coincidence , someone's just returned two tickets and I picked them .  
 Person2:Matinee or evening ?  
 Person1:        Evening .  
 Person2:Circle or stalls ?  
 Person1:        Stalls .  
 Person2:Wonderful , I'll go with you . 

informal