#include <bits/stdc++.h>
using namespace std;
#include <atcoder/all>
using namespace atcoder;
using mint = modint998244353;
int main () {
	int N, K;
	cin >> N >> K;
	std::vector dp(K + 1, vector(N + 1, mint(0)));
	mint iv = mint(N).inv();
	dp[0][0] = 1;
	for (int k = 0; k < K; k ++) {
		for (int n = 0; n <= N; n ++) {
			if (n) {
				dp[k+1][n-1] += dp[k][n] * n * iv;
			}
			if (n < N) {
				dp[k+1][n+1] += dp[k][n] * (N - n) * iv;
			}
		}
	}
	mint ans = N;
	for (int n = 0; n <= N; n ++) {
		ans += dp[K][n] * ((K - n) / 2);
	}
	cout << ans.val() << endl;
}