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:     So , what happened ? 
 Person2:  He never came . 
 Person1:      He stood you up . 
 Person2:  I wouldn ’ t exactly characterize it in that way . I think something happened . Something terrible and unexpected that made it impossible for him to ... what if he showed up , took one look at me and left ? 
 Person1:      Not possible . 
 Person2:  Maybe , there was a subway accident . 
 Person1:      Absolutely . 
 Person2:  A train got trapped underground with him inside . 
 Person1:      And no phone . 
 Person2:  And you know , how those express trains create suction . 

1