#include <atcoder/all>
#include <bits/stdc++.h>
#define rep(i, a, b) for (ll i = (ll)(a); i < (ll)(b); i++)
using namespace atcoder;
using namespace std;

typedef long long ll;

using mint = modint998244353;

int main() {
    int n, m;
    cin >> n >> m;
    vector<vector<mint>> dp(n + 1);
    dp[0].resize(m + 1);
    dp[0][0] = 1;
    rep(i, 0, n) {
        dp[i + 1] = dp[i];
        rep(j, 0, m + 1) {
            rep(k, 0, m + 1) {
                if (j + k + 1 <= m) {
                    dp[i + 1][j + k + 1] += dp[i][j] * dp[i][k];
                }
            }
        }
    }
    cout << dp[n][m].val() << endl;
}