#include <bits/stdc++.h>
using namespace std;
#include <atcoder/all>
using namespace atcoder;
using mint = modint998244353;
int main () {
	int N, Q;
	cin >> N >> Q;
	mint qsum = N;
	qsum = (qsum * (N + 1)) / 2;
	mint ans = 0;
	mint kai[1000020], fkai[1000020];
	kai[0] = 1;
	for (int i = 1; i <= N; i ++) {
		kai[i] = kai[i - 1] * i;
	}
	fkai[N] = kai[N].inv();
	for (int i = N; i ; i --) {
		fkai[i - 1] = fkai[i] * i;
	}
	auto comb = [&] (int n, int r) -> mint {
		if (n < 0 || r < 0 || n < r) return 0;
		return kai[n] * fkai[r] * fkai[n - r];
	};
	for (int d = 1; d <= N; d ++) {
		mint kj = kai[d] * kai[N - d] * comb(N, d - 1);
		ans += kj;
	}
	ans *= Q;
	ans *= qsum.pow(Q - 1);
	cout << ans.val() << endl;
}