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:       Have you received your TOWEL test results yet ?  
 Person2:Yes , I did . I passed !  
 Person1:        Congratulations ! I knew you could do it .  
 Person2:Well , I certainly couldn't have done it without your help . You are the best tutor I've ever had .  
 Person1:        Thank you , but it was your hard work that did it .  
 Person2:You deserve credit , too . I've learned so much from You . 

informal