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现在有$n(\geq 3)$个白色的球串成了一个圆环，编号依次为$1,2,\cdots,n$，现在你需要把这些球都染黑，具体操作为：
求出染黑所有白球的期望步数，答案对998244353取模。
从标准输入读入数据。
一行一个正整数$n$，表示白球的个数。
输出到标准输出。
一行一个数字，表示期望步数，对998244353取模。
42第一次操作后，只剩下一个白球。接下来，有两个黑球可以选择，一个白球可以选择，不管选哪一个都会染黑所有的球。
5499122179对于$40\%$的数据，$n\leq 10$。
对于$100\%$的数据，$n\leq 5000$。
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