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:       We'd like to have a look around your house ?  
 Person2:Yes , of course , please follow me .  
 Person1:        Thank you .  
 Person2:This is our courtyard .  
 Person1:        It's so spacious , about 40 square metres , right ?  
 Person2:Yes , about 46 square metres .  
 Person1:        Are these corn ears hanging on the tree branch ?  
 Person2:Yes .  
 Person1:        Very beautiful and very interesting . But why do you hang them in the tree ?  
 Person2:They don't have enough time to peel it after they harvested them , so they hung them in the tree . Then in winter , they can peel corn ears in their leisure time .  
 Person1:        Very good idea . Sometimes such pictures can show the house's richness . 

informal