输入1
3 1 3 3 5 5 7
输出1
4
输入2
10 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20
输出2
1024
以下是被hack的题解：
https://www.luogu.com.cn/article/0jvn1zfz https://www.luogu.com.cn/article/5bcntd27 https://www.luogu.com.cn/article/c9ulnxs9 https://www.luogu.com.cn/article/phsgx6le https://www.luogu.com.cn/article/agtfff55 https://www.luogu.com.cn/article/2563y2g7 https://www.luogu.com.cn/article/cmsb4qsv
这个题解和这道题目有关系吗？
https://www.luogu.com.cn/article/twd8kxl5
