Contest Clarifications

Problem 1003 样例 5怎么得到7的，求解释

ZZZ1234 | 2015-11-28 19:41:30Author

rt

admin | 2015-11-28 19:42:14# 1

看Hint

ZZZ1234 | 2015-11-28 19:47:12# 2

hint？

admin | 2015-11-28 19:47:59# 3

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