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:       Congratulations ! I heard that you are going to take a two-week training course in the headquarter .  
 Person2:Thank you . I am very happy to have this opportunity to learn something new . You know information and knowledge in this field update very fast .  
 Person1:        Sure it is . This is a changing world . Does the training course cover the new law and regulation issued last month ? They are very useful for us .  
 Person2:Yes , according to the agenda , there will be a seminar on these issues at the very beginning of the training course .  
 Person1:        Well , good for you . I hope you can get what you want from the training .  
 Person2:I will do my best . 

informal