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:       So , are you enjoying the performance so far ?  
 Person2:Well , the costumes and the set are marvellous , but the acting is a bit stiff . What do you think ?  
 Person1:        I think you're being a little critical . The actor in the lead role is fantastic . I suppose the chorus could be a bit better , though .  
 Person2:Do you know anyone in the play ?  
 Person1:        Actually , the woman playing Ophelia is a past classmate of mine .  
 Person2:Really ? Is that why you wanted to come to the play ?  
 Person1:        That's only part of it . I absolutely adore this director . Every play he works on turns out great .  
 Person2:So you've seen other plays that he's directed ?  
 Person1:        Quite a few actually . By the way , after the play , there's always a big party for the cast and their friends . My friend has invited us . Do you want to go ?  
 Person2:Sure , I'd love to meet the cast ! Have you ever been in a play ?  
 Person1:        I've never had a part in a play before , but I used to be a part of the stage crew in high school .  
 Person2:What did you do ?  
 Person1:        I helped build the sets and find props for the plays . What about you ?  
 Person2:I once helped out with costumes , but I didn't enjoy it very much .  
 Person1:        Why not ?  
 Person2:I spent over three weeks sewing sequins on a coat .  
 Person1:        That sounds kind of boring . Oh , look . They're dimming the lights . I think we should get back to our seats for the second half of the play . 

informal