#include <bits/stdc++.h>
#include <atcoder/all>
using namespace std;
using ll = long long;
using mint = atcoder::modint998244353;

mint binom(long long int a, long long int b){
    mint ans = 1, div = 1;
	int cnt = 0;
    b = min(b, a - b);
    for(int i = 0; i < b; i++){
		if(a - b + i + 1 == mint::mod()) cnt++;
        else ans *= a - b + i + 1;
		if(i + 1 == mint::mod()) cnt--;
        else div *= i + 1;
    }
	if(cnt >= 1) return 0;
	ans /= div;
    return ans;
}

int main() {
	ios::sync_with_stdio(false);
	cin.tie(0);
	int n, m;
	cin >> n >> m;
	int cyc = (mint(2).pow(n - 1) - 1).val();
	int cyc2 = cyc + cyc + 1;
	mint ans = binom(cyc2, m);
	if((1ll << min(60, n - 1)) >= m) ans -= cyc2 * binom(cyc, m - 1);
	cout << ans.val() << '\n';
}