#include<bits/stdc++.h>
namespace {
#pragma GCC diagnostic push
#pragma GCC diagnostic ignored "-Wunused-function"
#include<atcoder/all>
#pragma GCC diagnostic pop
using namespace std;
using namespace atcoder;
#define rep(i,n) for(int i = 0; i < (int)(n); i++)
#define rrep(i,n) for(int i = (int)(n) - 1; i >= 0; i--)
#define all(x) begin(x), end(x)
#define rall(x) rbegin(x), rend(x)
template<class T> bool chmax(T& a, const T& b) { if (a < b) { a = b; return true; } else return false; }
template<class T> bool chmin(T& a, const T& b) { if (b < a) { a = b; return true; } else return false; }
using ll = long long;
using P = pair<int,int>;
using VI = vector<int>;
using VVI = vector<VI>;
using VL = vector<ll>;
using VVL = vector<VL>;
using mint = modint998244353;

mint dp[3010][3010];
mint sr[3010];

} int main() {
  ios::sync_with_stdio(false);
  cin.tie(0);
  int n, m;
  cin >> n >> m;
  for(int j = 1; j <= m; j++) dp[0][j] = 1, sr[j]++;
  for(int i = 1; i <= n; i++) {
    rep(j, m + 1) if (i >= j) sr[j] -= dp[i - j][j];
    mint s;
    rep(j, m + 1) s += sr[j];
    if (i == n) {
      mint ans = mint(m).pow(n) - s;
      cout << ans.val() << endl;
      break;
    }
    for(int j = 1; j <= m; j++) dp[i][j] = s - sr[j];
    rep(j, m + 1) sr[j] += dp[i][j];
  }
  // rep(i, n) rep(j, m + 1) cout << dp[i][j].val() << " \n"[j == m];
}