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:       You look happy .  
 Person2:I am happy . I just bought a new car .  
 Person1:        Wow ! Is it a good car ?  
 Person2:It ’ s a great car . It ’ s very comfortable and it goes really fast .  
 Person1:        Was it expensive ?  
 Person2:Put it this way – it wasn ’ t cheap .  
 Person1:        What colour is it ?  
 Person2:It ’ s red and black . 

informal