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:       My god , it's such a lovely lake ! The lake has a water surface of 56 square kilometers .  
 Person2:No wonder it looks so huge .  
 Person1:        We are now walking on what is in fact an island . Here we get one of the 10 sceneries of the West Lake , Autumn Moon over the Calm Lake .  
 Person2:Why is it called Autumn Moon over the Calm Lake ?  
 Person1:        It's so named because in the pavilion over there the great poet Bai Buyi of the Tang Dynasty would take a rest after drinking a little too much , and watch the moon over the lake .  
 Person2:Very romantic .  
 Person1:        Now let's board the boat and have a ride on the lake .  
 Person2:Sure ( They get on the boat ) .  
 Person1:        Wang , what's that building over there ? It looks like some sort of a huge pavilion .  
 Person2:You are right . That's the Heart of Lake Pavilion , situated on an islet.It was built in 1552 and is the largest pavilion on the West Lake . Oh , here we are at the Little Yingzhou island . Let's get off the boat . Please watch your steps . 

informal