CF 赛制测试

Why did you guess the answer of problem C?
I think the Dinic is easy to code.

The solution of problem C is in the lotteries-13.zip.

invitation code: f50d

目前测试结果：

• 赛时可以只评测 pretest（如B 题有 20 个点，赛时只测了 pretests 1-10）。
• 分数会递减。
• 错误提交扣 50 分。
• bug：过了 pretests 也只有 pretests 的分。如 B 题 pretests passed 了只有一半的分；不会跑 System test