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 heard that you went to the concert the day before ? How did you like it ?  
 Person2:It was terrific.The concert was really a hit.The symphony orchestra was so good that I was completely absorbed in their performance .  
 Person1:        Who was the conductor ?  
 Person2:Oh , speaking of the conductor , he is indeed a genius.He did a perfect job.His name is Menuhin , a descendent of Russian American immigrants .  
 Person1:        Oh , I learned that he is also a legendary violinist .  
 Person2:Absolutely right.He gave a performance of Felix Mendelssohn's violin concerto.That caused a sensation.The audience were stunned by his pure tone .  
 Person1:        Obviously you did enjoy the concert .  
 Person2:Yes , I did . 

informal