#include <bits/stdc++.h>
#include <atcoder/all>
using namespace std;
using namespace atcoder;
//using mint = modint1000000007;
//const int mod = 1000000007;
using mint = modint998244353;
const int mod = 998244353;
//const int INF = 1e9;
//const long long LINF = 1e18;
#define rep(i, n) for (int i = 0; i < (n); ++i)
#define rep2(i,l,r)for(int i=(l);i<(r);++i)
#define rrep(i, n) for (int i = (n-1); i >= 0; --i)
#define rrep2(i,l,r)for(int i=(r-1);i>=(l);--i)
#define all(x) (x).begin(),(x).end()
#define allR(x) (x).rbegin(),(x).rend()
#define endl "\n"
#define P pair<int,int>
template<typename A, typename B> inline bool chmax(A & a, const B & b) { if (a < b) { a = b; return true; } return false; }
template<typename A, typename B> inline bool chmin(A & a, const B & b) { if (a > b) { a = b; return true; } return false; }
mint dp[3003][3003];
mint sumdp[3003];
int main() {
	ios::sync_with_stdio(false);
	cin.tie(nullptr);
	int n, m; cin >> n >> m;
	mint ans = pow_mod(m, n, mod);
	dp[1][0] = 1;
	sumdp[1] = 1;
	// 貰うdp
	rep2(i, 1, n + 1) {
		rep(j, m + 1) {
			int l = max(0, i - j + 1);
			int r = i;
			if (l <= r) {
				dp[i + 1][j] += sumdp[r] - sumdp[l];
				dp[i + 1][j] -= dp[r][j] - dp[l][j];
			}
			dp[i + 1][j] += dp[i][j];
			sumdp[i + 1] += dp[i + 1][j] - dp[i][j];
		}
		sumdp[i + 1] += sumdp[i];
	}
	rep2(i, 1, m + 1)ans -= dp[n + 1][i] - dp[n][i];
	cout << ans.val() << endl;
	return 0;
}