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:     I've just got a new printer . How often do I need to replace the print heads ? 
 Person2:  Well , under normal conditions each head lasts about 5 000 copies or so . It depends on the user , but about once a month is average . 
 Person1:      So if I don't print out very much , it could last a lot longer ? 
 Person2:  That's right . It could last six months or more . This model's designed for heavy use . Don't worry - you'll get an error message telling you when to change the head . 

1