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:       What's wrong with you ? 
 Person2:My head hurts badly . 
 Person1:        How long has it been like this ? 
 Person2:Since last night . 
 Person1:        Do you have a sleeping problem ? 
 Person2:Yes , I even can't fall asleep these days . 
 Person1:        I think you'd better have a further exam , and before the result comes out , try to relax yourself and take the medicine before you sleep . It will help you to kill the pain and make you sleep well . 
 Person2:Is it serious , Doctor ? 
 Person1:        When the result comes out , I will tell you about it . Remember , never be afraid or be too tired . 
 Person2:OK , thank you , Doctor . 

formal