Detailed Instructions: In this task you are given a premise and two alternatives in Chinese. You must choose the alternative that is more plausibly the 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.
Problem:男孩的背部疼痛。
(1)他的背包是开着的。(2)他的背包很重。
Solution:
2