#include <bits/stdc++.h>

using namespace std;

typedef pair<int, int> pii;
typedef long long ll;
const int N = 2000086, MOD = 998244353, INF = 0x3f3f3f3f;
ll res;
int n, m, cnt, w[N];


ll fac[N], inv[N], p[N];
inline ll qmi(ll a, ll b, ll c) { ll res = 1; while (b) { if (b & 1) res = res * a % c; a = a * a % c; b >>= 1; } return res; }
ll C(int a, int b) { if (a < b) return 0; return fac[a] * inv[b] % MOD * inv[a - b] % MOD; }
void init() {
	fac[0] = inv[0] = 1;
	for (int i = 1; i < N; i++) fac[i] = fac[i - 1] * i % MOD;
	inv[N - 1] = qmi(fac[N - 1], MOD - 2, MOD);
	for (int i = N - 2; i; i--) inv[i] = inv[i + 1] * (i + 1) % MOD;
	p[0] = C(n - 1, n - 1);
	for (int i = 1; i < N; i++) p[i] = (p[i - 1] + C(n - 1 + i, n - 1)) % MOD;
}


int main() {
	cin >> n >> m;
	init();
	ll g = qmi((p[m] - n + MOD) % MOD, MOD - 2, MOD);
	for (int i = 0; i * n <= m; i++) {
		if (i == m) break;
		ll t = 0;
		if ((i + 1) * n <= m) {
			t = p[m - (i + 1) * n];
		}
		ll sum = (p[m - i * n] - t + MOD) % MOD;
		res = (res + i * sum % MOD * g) % MOD;
	}
	printf("%lld\n", res);
	return 0;
}