Definition: You are given a conversation between two people. 'Person1:' and 'Person2:' are used to separate their respective dialogues. If the conversation begins with a question, label it '1' otherwise '0'.
Input:  Person1:     Do you know his sister ?  
 Person2:  Her name is Laura , isn't it ?  
 Person1:      That's right .  
 Person2:  How old is she ?  
 Person1:      Um ... let me see now , is it 18 or 19 , I can never remember ... 18 ... 19 next birthday . Tthat's it .  
 Person2:  What does she look like ?  
 Person1:      Well ...  
 Person2:  Pretty , is she ?  
 Person1:      Yes ... quite pretty . 

1