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:       I need your help , Bob .  
 Person2:What's the matter ?  
 Person1:        I'm really confused by these annoying abbreviations .  
 Person2:Just relax . That's because you're new to chat . Let me take a look .  
 Person1:        A / S / L , IGP , H & K , and ZZZ . What the hell do they mean ?  
 Person2:ZZZ means'sleepy or tired or bored ' , A / S / L is tricky , which is often used at first encounter . It's a three-word question , ' age , / sex / location ? '  
 Person1:        Interesting . Then what does H & K refer to ? The city of Hong Kong ?  
 Person2:Wrong . lt's not a place name , but a passionate act .  
 Person1:        Really ? What kind ? A girl left this word to me , and I thought she was in Hong Kong .  
 Person2:Ahahah ... you miss her point for sure . H & K actually is an acronym for ' hug and kiss ' .  
 Person1:        Hug and kiss ? ! How is it possible ? Oh , it's really bad to Miun - Verstand her meaning .  
 Person2:Yeah , seems that you have a lot to learn and memorize . 

informal