Problem B. Problem B. Beads
时间限制 4000 ms
内存限制 512 MB
There are m different colors of beads. Define a necklace of length n is a cyclic string that successively connects n beads, taking all rotations and overturnings as equivalent.
For example, [1, 2, 3, 4] is equivalent to [2, 3, 4, 1], [3, 4, 1, 2] and [4, 1, 2, 3] (by ro-tation); and [1, 2, 3, 4] is equivalent to [1, 4, 3, 2], [3, 2, 1, 4], [2, 1, 4, 3] and [4, 3, 2, 1] (by overturning).
Moreover, each time you could transpose the beads of color i to color (i mod m) + 1 for all i at the same time.
After some operations, if a necklace A becomes B, then B is equivalent to A.
Count the number of necklaces modulo 998244353.
输入数据
输出数据
For each test case, output one line contains a single integer, denoting the number of necklaces modulo 998244353.
样例输入
复制
5
3 2
4 2
8 5
9 5
2333 333
样例输出
复制
2
4
5079
22017
544780894
样例说明
For n = 3, m = 2:
- [1, 1, 1], [2, 2, 2] are equivalent
- [1, 1, 2], [1, 2, 1], [2, 1, 1], [2, 2, 1], [2, 1, 2], [1, 2, 2] are equivalent
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