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 ? Your golden watch is lost ?  
 Person2:Yeah . I just can't find it anywhere .  
 Person1:        It's an open book that it was stolen by the man in black .  
 Person2:Let's get it back . 

informal