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:       It's very dark in here.Will you turn on the light ? 
 Person2:Okay.But our baby has fallen sleep . 
 Person1:        Then , turn on the lamp , please . 
 Person2:But where's the switch ? 
 Person1:        It's there by the window . 

formal