https://www.luogu.com.cn/article/r4whwtrx ， https://www.luogu.com.cn/article/fgb9uogc ， https://www.luogu.com.cn/article/d79yvlhs ， https://www.luogu.com.cn/article/6jfeot7f 均无证明过程。洛谷的题解貌似必须要有过程的吧/fad

https://www.luogu.com.cn/article/a2rcgvpm 错的离谱了，$2^p-1$ 打成 $2^{p-1}$ 了/fad