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:       Welcome to Super Stereos . What can I do for you ?  
 Person2:I'd like to look at your stereo systems . Do you have anything on sale ?  
 Person1:        Yes , this system over here is on sale for $ 1,000 . As you can see , all of the components are brand-name .  
 Person2:But it doesn't have a turntable . I have a fair number of vinyl records , so I need something to play them on .  
 Person1:        Our selection of stereo systems with turntables is somewhat limited , but we do have this system over here . 

formal