Given a premise and two alternatives, choose the alternative that is a more plausible cause or effect of the situation described by the premise. The input format is "premise
(1)alternative_1(2)alternative_2", the output should either be "1" or "2" based on your judgment.
Q: I became enthralled in the book.
(1)I returned the book.(2)I lost track of time.
A: 
2