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:     Is there a train leaving for Philadelphia ?  
 Person2:  Yeah . There's an express that leaves in twenty minutes .  
 Person1:      May I buy a ticket here at the station ?  
 Person2:  Sure .  
 Person1:      Where ?  
 Person2:  Go to window number eleven .  
 Person1:      Thanks . 

1