#include <iostream>
#include <algorithm>
#include <utility>
#include <vector>
#include <numeric>
#include <array>

template <uint32_t Modulus>
class modular {
public:
  using value_type = uint32_t;
  using max_type = uint64_t;

  static constexpr value_type mod = Modulus;
  static constexpr value_type mod_min = 1;
  static constexpr value_type mod_max = 2147483647;
  static_assert(mod >= mod_min, "invalid mod :: too small");
  static_assert(mod <= mod_max, "invalid mod :: too big");

  template <class T>
  static constexpr value_type normalize(T value_) {
    if (value_ < 0) {
      value_ = -value_;
      value_ %= mod;
      if (value_ == 0) return 0;
      return mod - value_;
    }
    return value_ % mod;
  }

private:
  value_type value;

public:
  constexpr modular(): value(0) { }
  template <class T>
  explicit constexpr modular(T value_): value(normalize(value_)) { }
  template <class T>
  explicit constexpr operator T() { return static_cast<T>(value); }

  constexpr value_type operator () () const { return value; }
  constexpr modular operator - () const { return modular(mod - value); }
  constexpr modular operator ~ () const { return inverse(); }

  constexpr value_type &extract() { return value; }
  constexpr modular inverse() const { return power(mod - 2); }
  constexpr modular power(max_type exp) const {
    modular res(1), mult(*this);
    while (exp > 0) {
      if (exp & 1) res *= mult;
      mult *= mult;
      exp >>= 1;
    }
    return res;
  }

  constexpr modular operator + (const modular &rhs) const { return modular(*this) += rhs; }
  constexpr modular& operator += (const modular &rhs) { 
    if ((value += rhs.value) >= mod) value -= mod; 
    return *this; 
  }

  constexpr modular operator - (const modular &rhs) const { return modular(*this) -= rhs; }
  constexpr modular& operator -= (const modular &rhs) { 
    if ((value += mod - rhs.value) >= mod) value -= mod; 
    return *this; 
  }

  constexpr modular operator * (const modular &rhs) const { return modular(*this) *= rhs; }
  constexpr modular& operator *= (const modular &rhs) { 
    value = (max_type) value * rhs.value % mod;
    return *this;
  }

  constexpr modular operator / (const modular &rhs) const { return modular(*this) /= rhs; }
  constexpr modular& operator /= (const modular &rhs) { return (*this) *= rhs.inverse(); }

  constexpr bool zero() const { return value == 0; }
  constexpr bool operator == (const modular &rhs) const { return value == rhs.value; }
  constexpr bool operator != (const modular &rhs) const { return value != rhs.value; }
  friend std::ostream& operator << (std::ostream &stream, const modular &rhs) {
    return stream << rhs.value;
  }

};

template <class T, std::size_t N>
class factorials {
public:
  using value_type = T;
  static constexpr std::size_t size = N;

public:
  std::array<value_type, size + 1> fact{};
  std::array<value_type, size + 1> fact_inv{};

  factorials() {
    fact.front() = value_type(1);
    for (std::size_t i = 1; i <= size; ++i) {
      fact[i] = fact[i - 1] * value_type(i);
    }
    fact_inv.back() = ~fact.back();
    for (std::size_t i = size; i > 0; --i) {
      fact_inv[i - 1] = fact_inv[i] * value_type(i);
    }
  }

  value_type operator () (std::size_t n, std::size_t r) const {
    return fact[n] * fact_inv[n - r] * fact_inv[r];
  }

};

using modint = modular<998244353>;
factorials<modint, 3000> fact;

int main() {
  int N, X;
  std::cin >> N >> X;
  modint ans;
  for (int one = 0; one <= N; ++one) {
    for (int two = 0; one + two <= N; ++two) {
      int sum = one + 2 * two;
      if (sum < X) {
        ans += fact(N, one) * fact(N - one, two);
      }
      if (sum > X) {
        if ((sum - (X - 1)) % 2 == 0) {
          if (sum >= 2 * (X - 1)) {
            if (one == 0) {
              ans += fact(N, two);
            }
          }
          else {
            int mid = 2 * (X - 1) - sum;
            if (one <= mid) {
              ans += fact(one + (mid - one) / 2, one) * fact(N, N - one - two);
            }
          }
        }
      }
    }
  }
  std::cout << ans << '\n';
  return 0;
}


Measured memory_bytes: 256