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:       Is this Mr.Smith ' s residence ? 
 Person2:Yes , it is . 
 Person1:        My name is Paul.Is Mr.Smith in ? 
 Person2:Yes , he is . 

formal