#include <bits/stdc++.h>
using namespace std;
using ll = long long;
ll const m = 998244353;
ll mpow(ll a, ll n) {
	ll ret = 1;
	while (n) {
		if (n & 1) ret = (ret * a) % m;
		n >>= 1;
		a = (a * a) % m;
	}
	return ret;
}
int main() {
	int N, M;
	cin >> N >> M;
	ll kai[400040], fkai[400040];
	kai[0] = 1;
	for (int i = 1; i <= M * 2; i ++) {
		kai[i] = (kai[i - 1] * i) % m;
	}
	fkai[M * 2] = mpow(kai[M * 2], m - 2);
	for (int i = M * 2; i > 0; i --) {
		fkai[i - 1] = (fkai[i] * i) % m;
	}
	ll ans = 0;
	auto comb = [&](int n, int r) -> ll {
		if (r < 0 || n < r) return 0ll;
		ll ret = (kai[n] * fkai[r]) % m;
		ret = (ret * fkai[n - r]) % m;
		return ret;
	};
	for (int x = 1; x <= M; x ++) {
		int n = (x - 1) * 2;
		ans += comb(n, N - 1);
		ans %= m;
	}
	cout << ans << endl;
}