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#18560. 红黑图

الإحصائيات

考虑一个有 $n$ 个顶点的无向图,顶点编号为 $1$ 到 $n$,每个顶点都被染成红色或黑色。如果一个图满足以下两个条件,则称其是优美的(beautiful):

  • 删去所有两端点均为红色的边后,图是一棵树;
  • 删去所有两端点均为黑色的边后,图是一棵树。

如果一个图是优美的,且其边数不小于任何其他具有相同顶点数的优美图的边数,则称该图是最优的(best)。

你的任务是计算具有 $n$ 个顶点的最优图的数量。如果两个图的边集不同,或者至少一个顶点的颜色不同,或者两者皆有,则认为这两个图是不同的。由于答案可能很大,请将其对 $998\,244\,353$ 取模后输出。

输入格式

仅包含一行,一个整数 $n$ ($2 \le n \le 10^6$)。

输出格式

输出一个整数,表示具有 $n$ 个顶点的最优图的数量,对 $998\,244\,353$ 取模。

样例

输入样例 1

3

输出样例 1

6

输入样例 2

4

输出样例 2

12

输入样例 3

5

输出样例 3

240

输入样例 4

6

输出样例 4

1080

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