#include <bits/stdc++.h>
using namespace std;
#include <atcoder/modint>
using namespace atcoder;
using mint = modint998244353;

int main(){
	int N, M;
	cin >> N >> M;
	vector<mint> ex(M + N + 1, 1), re(M + N + 1, 1);
	for(int i = 1; i <= M + N; i++){
		ex[i] = i * ex[i - 1];
		re[i] = ex[i].inv();
	}
	mint ans = 0;
	for(int i = 1; i <= M / N; i++) ans += ex[M - N * i + N] * re[N] * re[M - N * i];
	if(N == 1) ans -= M;
	ans /= ex[M + N] * re[N] * re[M] - N;
	cout << ans.val() << endl;
	return 0;
}