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:       Are you have a hand in locking into the case ? 
 Person2:Yes . 
 Person1:        How do you feel about it ? 
 Person2:It is really a hard nut to crack . The problem is that the crime was done without leaving any trace . 

formal