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:       The Great Wall is a great attraction for visitors .  
 Person2:It's a man-made wonder . I've seen it many times in textbooks and it's part of my dream to visit it .  
 Person1:        Someone claimed it was one of the two man-made wonders that could be seen on the moon .  
 Person2:That's true . 

informal