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:     Hello , ma'am . Can I help you ?  
 Person2:  Yes , please . I'd like a gin and tonic .  
 Person1:      Sure , ma'am . Here you are .  
 Person2:  Thank you . How much is it ?  
 Person1:      25 yuan .  
 Person2:  Here's 30 . Keep the change .  
 Person1:      Thank you very much , ma'am , but we don't take tips in China . 

1