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:       Grandpa , this restaurant looks really old ! How long ago was it built ?  
 Person2:I'm not sure when it started . But I know it's older than me . As a young boy , I used to eat here a lot .  
 Person1:        Oh , it's interesting . Dad told me you brought him here when he was young , too . Now , it's my turn .  
 Person2:Yeah . We are the VIP customers here . So , what do you want to eat today ?  
 Person1:        I'd like to eat a hamburger and a bottle of coca-cola .  
 Person2:Hey , kid , that's wrong . It's a Chinese restaurant . Let's eat something traditional .  
 Person1:        Then there is nothing particular I'd like to eat . Grandpa , what's your favorite here ?  
 Person2:The Chinese rice pudding . Your father loves it , too . You wanna try ?  
 Person1:        Sure . Is it sweet ?  
 Person2:Yes , of course . But I think they can make you a salty one , too .  
 Person1:        Great , I want it spicy .  
 Person2:Come on . Don's go too far .  
 Person1:        I want it to be special . And you know that I always like hot food .  
 Person2:OK then . We shall ask them to put some red chilli on it . 

informal