#include<bits/stdc++.h>
#define int long long
using namespace std;
const int N = 1e6 + 7, M = 998244353;
mt19937_64 rd(chrono::steady_clock::now().time_since_epoch().count());
int i, j, k=1, n, m, res;
int v[N], f[N];

int C(int x, int y) {
	return f[x] * v[y] % M * v[x-y] % M;
}

int F(int x, int y) {
	return (C(x+y, x) * C(x+y, x) % M - C(x+y, y-1) * C(x+y, y+1) % M + M) % M;
}

signed main() {
	v[0] = v[1] = f[0] = f[1] = 1;
	for(i=2; i<N; i++) {
		f[i] = f[i-1] * i % M;
		v[i] = (M - M / i) * v[M % i] % M;
	}
	for(i=2; i<N; i++) v[i] = v[i] * v[i-1] % M;
	cin >> n >> m;
	for(i=0; i<=min(n, m-1); i++,k*=-1) (res += k * C(n, i) % M * F(n, m-i) % M + M) %= M;//, cout << i << " " << C(n, i) << " " << k << " " << F(n, m-i) << "\n";
	cout << res + 1;
	return 0;
}