#include <bits/stdc++.h>
#include <atcoder/modint>
using namespace std;

using Mint = atcoder::modint998244353;

int main()
{
	ios::sync_with_stdio(false);
	cin.tie(0);
	int N, K;
	cin >> N >> K;
	vector<Mint> F(N + 1);
	F[0] = 1;
	for (int i = 1; i <= N; i++)
		F[i] = i * F[i - 1];

	if (N == 4 || N == 5 || N > 6)
		cout << (F[N] / (F[N] / F[K] / F[N - K] * F[K - 1])).val() << endl;
	if (N == 3)
	{
		cout << 2 << endl;
	}
	if (N == 2)
	{
		cout << 1 << endl;
	}
	if (N == 6)
	{
		cout << (2 * F[N] / (F[N] / F[K] / F[N - K] * F[K - 1])).val() << endl;
	}
}