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#959. 倍數?

الإحصائيات

畀定一個整數 $n$。如果一個序列嘅元素都喺 $[1,n]$ 入面,而且佢所有非空子序列(唔一定連續)嘅元素總和都唔可以畀 $n$ 整除,就稱呢個序列為好序列。

計出長度為 $n-k$ 嘅好序列數目,對 $998\,244\,353$ 取模。

輸入

輸入只有一行,包含兩個整數 $n,k$($1 \le k \le n/4<n<998\,244\,353$)。

輸出

輸出一個數——本題嘅答案。

樣例

輸入 1

4 1

輸出 1

2

輸入 2

9 2

輸出 2

48

輸入 3

222222222 222222

輸出 3

851798824

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