#include <bits/stdc++.h>

using LL = long long;

const int N = 2e6 + 7;
const int MOD = 998244353;

int inv[N];

int main() {

  inv[1] = 1;
  for(int i = 2; i < N; ++i)
    inv[i] = MOD - 1LL * MOD / i * inv[MOD % i] % MOD;
  
  int n, m;

  scanf("%d%d", &n, &m);

  int ans = n;
  for(int i = 1; i <= 2 * n + 1; ++i)
    ans = 1LL * ans * inv[i] % MOD * (2 * n + m - i + 1) % MOD;

  printf("%d\n", ans);
  
  return 0;
}