#include <bits/stdc++.h>
using namespace std;
using ll = long long;
using ld = long double;
using pll = pair<ll, ll>;
using tlll = tuple<ll, ll, ll>;
constexpr ll INF = 1LL << 60;
template<class T> bool chmin(T& a, T b) {if (a > b) {a = b; return true;} return false;}
template<class T> bool chmax(T& a, T b) {if (a < b) {a = b; return true;} return false;}
ll safemod(ll A, ll M) {ll res = A % M; if (res < 0) res += M; return res;}
ll divfloor(ll A, ll B) {if (B < 0) {return divfloor(-A, -B);} return (A - safemod(A, B)) / B;}
ll divceil(ll A, ll B) {if (B < 0) {return divceil(-A, -B);} return divfloor(A + B - 1, B);}
ll pow_ll(ll A, ll B) {ll res = 1; for (int i = 0; i < B; i++) {res *= A;} return res;}
ll arisum_ll(ll a, ll d, ll n) { return n * a + (n & 1 ? ((n - 1) >> 1) * n : (n >> 1) * (n - 1)) * d; }
ll arisum2_ll(ll a, ll l, ll n) { return n & 1 ? ((a + l) >> 1) * n : (n >> 1) * (a + l); }
ll arisum3_ll(ll a, ll l, ll d) { assert((l - a) % d == 0); return arisum2_ll(a, l, (l - a) / d + 1); }
template<class T> void unique(vector<T> &V) {V.erase(unique(V.begin(), V.end()), V.end());}
template<class T> void sortunique(vector<T> &V) {sort(V.begin(), V.end()); V.erase(unique(V.begin(), V.end()), V.end());}
#define FINALANS(A) do {cout << (A) << '\n'; exit(0);} while (false)
template<class T> void printvec(const vector<T> &V) {int _n = V.size(); for (int i = 0; i < _n; i++) cout << V[i] << (i == _n - 1 ? "" : " ");cout << '\n';}
template<class T> void printvect(const vector<T> &V) {for (auto v : V) cout << v << '\n';}
template<class T> void printvec2(const vector<vector<T>> &V) {for (auto &v : V) printvec(v);}
//*
#include <atcoder/all>
using namespace atcoder;
using mint = modint998244353;
//using mint = modint1000000007;
//using mint = modint;
//*/

template<class T> class combination
{
public:
  vector<T> fac, finv, inv;

  combination(int M)
  {
    fac.resize(M + 1);
    finv.resize(M + 1);
    inv.resize(M + 1);

    //*
    fac[0] = T(1);
    for (int i = 1; i <= M; i++)
      fac[i] = fac[i - 1] * mint::raw(i);
    finv[M] = fac[M].inv();
    for (int i = M - 1; i >= 0; i--)
      finv[i] = finv[i + 1] * mint::raw(i + 1);
    for (int i = 1; i <= M; i++)
      inv[i] = fac[i - 1] * finv[i];
    //*/

    /*
    fac[0] = T(1), finv[0] = T(1);
    fac[1] = T(1), finv[1] = T(1), inv[1] = T(1);
    for (int i = 2; i <= M; i++)
    {
      fac[i] = fac[i - 1] * i;
      inv[i] = -inv[T::mod() % i] * (T::mod() / i);
      finv[i] = finv[i - 1] * inv[i];
    }
    //*/
  }

  T P(int N, int K)
  {
    if (N < K) return 0;
    if (N < 0 || K < 0) return 0;
    return fac[N] * finv[N - K];
  }

  T C(int N, int K)
  {
    if (N < K) return 0;
    if (N < 0 || K < 0) return 0;
    return fac[N] * finv[K] * finv[N - K];
  }

  T H(int N, int K)
  {
    if (N == 0 && K == 0)
      return 1;
    return C(N + K - 1, K);
  }
};

int main()
{
  ll a, b;
  cin >> a >> b;

  combination<mint> com(200010);
  mint ans = com.C(a + b - 2, a - 1);
  cout << ans.val() << endl;
}