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'm going on a guided tour in the mountain .  
 Person2:You'll see the world-famous magnificent waterfall .  
 Person1:        I like the sight and the sound . It worked on me like a magic when I was a child  
 Person2:Your dream will come true . It's really breathtaking 

informal