#include <bits/stdc++.h>
using namespace std;
long long n, d, dp[569][569], ps[2][569][569], dv = 998244353;
int main() {
  long long i, j, z = 0;
  scanf("%lld%lld", &n, &d);
  dp[0][0] = 1;
  for (i = 0; i <= n; i++) {
    ps[0][0][i] = 1;
  }
  for (i = 1; i <= n; i++) {
    for (j = 1; j <= n; j++) {
      if (j <= i) {
        dp[i][j] = (ps[0][i - j][j - 1] + ps[1][i - 1][j] + dv -
                    ps[1][max(i - j - 1, 0ll)][j]) %
                   dv;
      }
      ps[0][i][j] = (ps[0][i][j - 1] + dp[i][j]) % dv;
      ps[1][i][j] = (ps[1][i - 1][j] + dp[i][j]) % dv;
    }
  }
  for (i = 1; i <= n; i++) {
    z = (z + dp[n][i] * ps[0][n][min((d - 1) / i, n)]) % dv;
  }
  z = z * 2 % dv;
  printf("%lld\n", z);
}
