#include <algorithm>
#include <cmath>
#include <iostream>
#include <map>
#include <numeric>
#include <queue>
#include <set>
#include <vector>
using namespace std;
using ll = long long;
#define rep(i, j, n) for (ll i = j; i < (n); ++i)
#define rrep(i, j, n) for (ll i = (n)-1; j <= i; --i)
#define all(a) a.begin(), a.end()
template <typename T>
std::ostream &operator<<(std::ostream &os, std::vector<T> &a) {
  for (size_t i = 0; i < a.size(); ++i) os << (i > 0 ? " " : "") << a[i];
  return os << '\n';
}
template <typename T>
std::istream &operator>>(std::istream &is, std::vector<T> &a) {
  for (T &x : a) { is >> x; }
  return is;
}

[[maybe_unused]] constexpr long long MOD = 998244353;
// constexpr long long MOD = 1000000007;
[[maybe_unused]] constexpr int INF = 0x3f3f3f3f;
[[maybe_unused]] constexpr long long INFL = 0x3f3f3f3f3f3f3f3fLL;

template <long long mod = 1000000007>
class modint {
public:
  long long x;
  constexpr modint(const long long x = 0) noexcept : x(x % mod) {}
  constexpr long long &value() noexcept { return x; }
  constexpr const long long &value() const noexcept { return x; }
  constexpr modint operator+(const modint rhs) const noexcept {
    return modint(*this) += rhs;
  }
  constexpr modint operator-(const modint rhs) const noexcept {
    return modint(*this) -= rhs;
  }
  constexpr modint operator*(const modint rhs) const noexcept {
    return modint(*this) *= rhs;
  }
  constexpr modint operator/(const modint rhs) const noexcept {
    return modint(*this) /= rhs;
  }
  constexpr modint &operator+=(const modint rhs) noexcept {
    if ((x += rhs.x) >= mod) x -= mod;
    return *this;
  }
  constexpr modint &operator-=(const modint rhs) noexcept {
    if ((x += mod - rhs.x) >= mod) x -= mod;
    return *this;
  }
  constexpr modint &operator*=(const modint rhs) noexcept {
    x = x * rhs.x % mod;
    return *this;
  }
  constexpr modint &operator/=(const modint rhs) noexcept {
    *this *= rhs.inverse();
    return *this;
  }
  constexpr bool operator==(const modint &rhs) const { return x == rhs.x; }
  constexpr bool operator!=(const modint &rhs) const { return x != rhs.x; }
  modint inverse() const {
    long long a = x, b = mod, u = 1, v = 0, t;
    while (b > 0) {
      t = a / b;
      swap(a -= t * b, b);
      swap(u -= t * v, v);
    }
    return modint(u + mod);
  }

  modint pow(long long exp) const {
    modint res(1), mul(x);
    while (exp > 0) {
      if (exp & 1) res *= mul;
      mul *= mul;
      exp >>= 1;
    }
    return res;
  }
  operator long long() const { return x; }
  friend ostream &operator<<(ostream &os, const modint &rhs) {
    return os << rhs.x;
  }
  friend istream &operator>>(istream &is, modint &a) {
    long long t;
    is >> t;
    a = modint<mod>(t);
    return is;
  }
};

int main() {
  cin.tie(0)->sync_with_stdio(0);
  using mint = modint<MOD>;
  ll n, m;
  cin >> n >> m;

  mint ans = 1;
  rep(i, 0, n * 2 + 1) ans *= mint(n * 2 + m - i) * mint(i + 1).inverse();
  cout << ans * mint(n);
}