#include <iostream>
using namespace std;
using LL = long long int;
const LL M = 998244353;
LL ex(LL a, LL b) {
	LL ans = 1, e = a;
	while(b) {
		if(b & 1) { (ans *= e) %= M; }
		(e *= e) %= M;
		b >>= 1;
	}
	return ans;
}
int main() {
	LL n, k; cin >> n >> k;
	LL ans = ex(k, n + 1);
	for(LL i = 1; i <= k - 1; i++) {
		(ans -= (k * n - i * (n - 1)) % M * ex(i, n - 1)) %= M;
	}
	ans = (ans + M) % M;
	cout << ans << endl;
}