#pragma GCC target("avx2")
#pragma GCC optimize("O3")
#pragma GCC optimize("Ofast,unroll-loops")
#include <bits/stdc++.h>
#include <atcoder/all>
#define rep(i, n) for (int i = 0; i < n; i++)
#define ALL(a) a.begin(), a.end()
#define ll long long
using namespace std;
using namespace atcoder;
constexpr int mod = 998244353;
using mint = modint998244353;
mint fac[5050];
mint inv[5050];
void solve()
{
	fac[0] = 1;
	for (int i = 1; i < 5050; i++)
		fac[i] = i * fac[i - 1];
	inv[5049] = 1 / fac[5049];
	for (int i = 5049; i > 0; i--)
		inv[i - 1] = i * inv[i];
	int n, m;
	cin >> n >> m;
	mint ans = 0;
	for (int k = 1; k <= n; k++)
	{
		mint mul = fac[n] * inv[k] * inv[n - k];
		if ((n - k) & 1)
			mul = -mul;
		mul *= mint(k).pow(n + m);
		ans += mul;
	}
	mint ff = 1;
	for (int i = 1; i <= n; i++)
		ff *= i + m;
	ans /= ff * mint(n).pow(m);
	cout << ans.val() << '\n';
}
int main()
{
	cin.tie(nullptr);
	ios::sync_with_stdio(false);
	cout << fixed << setprecision(13);
	solve();
	return 0;
}