#include "bits/stdc++.h"
#include<vector>
#include<iostream>
#include<queue>
#include<algorithm>
#include<map>
#include<set>
#include<iomanip>
#include<assert.h>
#include<unordered_map>
#include<unordered_set>
#include<string>
#include<stack>
#include<complex>
#include<memory>

#pragma warning(disable:4996)
using namespace std;
using ld = long double;
template<class T>
using Table = vector<vector<T>>;
const ld eps=1e-9;
using Graph=vector<vector<int>>;
using ll=long long;
#define WHATS(var)cout<<__LINE__<<' '<<#var<<"="<<var<<endl;
	
template<class S, class T> ostream& operator <<(ostream &os, const pair<S, T> v){
	os << "( " << v.first << ", " << v.second << ")"; return os;
}
template<class T> ostream& operator <<(ostream &os, const vector<T> &v){
	for(int i = 0; i < v.size(); i++){if(i > 0){os << " ";} os << v[i];} return os;
}
template<class T> ostream& operator <<(ostream &os, const vector<vector<T>> &v){
	for(int i = 0; i < v.size(); i++){if(i > 0){os << endl;} os << v[i];} return os;
}
template<class T> ostream& operator <<(ostream &os, const vector<set<T>> &v){
	for(int i = 0; i < v.size(); i++){if(i > 0){os << endl;} os << v[i];} return os;
}
template<class T> ostream& operator <<(ostream &os, const set<T> &v){
	int i=0;
	for(auto it:v){
		if(i > 0){os << ' ';}
		os << it;
		i++;
	} 
	return os;
}

using ll=long long;
using ld = long double;
#include<vector>
const ll mod = 998244353;
ll mod_pow(ll a, ll n) {
	ll res = 1;
	while (n) {
		if (n & 1)res = res * a%mod;
		a = a * a%mod; n >>= 1;
	}
	return res;
}
ll mod_inverse(ll a) {
	return mod_pow(a, mod - 2);
}
ll root[24], invroot[24];
void init() {
    static bool flag=false;
    if(!flag){
        flag=true;
        for(int i=0;i<24;++i) {
            int n = (1 << i);
            root[i] = mod_pow(3, (mod - 1) / n);
            invroot[i] = mod_inverse(root[i]);
        }
    }
	
}
typedef vector <ll> poly;
poly dft(poly f, bool inverse = false) {
    init();
	int n = f.size(); int i, j, k;
	//bit左右反転
	for (i = 0, j = 1; j < n - 1; j++) {
		for (k = n >> 1; k >(i ^= k); k >>= 1);
		if (i > j)swap(f[i], f[j]);
	}
	for (int j = 1; (1 << j) <= n; j++) {
		int m = 1 << j;
		ll zeta = root[j];
		if (inverse)zeta = invroot[j];
		for (i = 0; i < n; i += m) {
			ll powzeta = 1;
			for (k = i; k < i + m / 2; k++) {
				ll t1 = f[k], t2 = powzeta * f[k + m / 2] % mod;
				f[k] = t1 + t2; while (f[k] >= mod)f[k] -= mod;
				f[k + m / 2] = t1 - t2 + mod; while (f[k + m / 2] >= mod)f[k + m / 2] -= mod;
				(powzeta *= zeta) %= mod;
			}
		}
	}
	if (inverse) {
		ll rv = mod_inverse(n);
		for (i = 0; i < n; i++) {
			(f[i] *= rv) %= mod;
		}
	}
	return f;
}
poly multiply(poly g, poly h) {
	int n = 1;
	int pi = 0, qi = 0;
	for(int i=0;i<g.size();++i)if (g[i])pi = i;
	for(int i=0;i<h.size();++i)if (h[i])qi = i;
	int sz = pi + qi + 2;
	while (n < sz)n *= 2;
	g.resize(n); h.resize(n);
	/*while (g.size() < n) {
	g.push_back(0);
	}
	while (h.size() < n) {
	h.push_back(0);
	}*/
	poly gg = dft(g);
	poly hh = dft(h);
	poly ff; ff.resize(n);
	for(int i=0;i<n;++i){
		ff[i] = gg[i] * hh[i] % mod;
	}
	return dft(ff, true);
}
int main() {
	ios::sync_with_stdio(false);
	cin.tie();
    init();
    int N,K;cin>>N>>K;
    ll now=1;

    vector<ll>p1(N+1);
    // 1/1 32/2 243/6 1024/24 ...
    for(int i=0;i<=N;++i){
        p1[i]=mod_pow(i+1,N)*now%mod;
        now=now*mod_pow(i+2,mod-2);
        now%=mod;
    }

    vector<ll>p2(N+1);
    // 1/1 1/(-1) 2/1 6/(-1) ...
    now=1;
    for(int i=0;i<=N;++i){
        p2[i]=now;
        now*=mod_pow(i+1,mod-2);
        now%=mod;
        now*=mod-1;
        now%=mod;
    }
    //WHATS(p1)
   // WHATS(p2)
    auto p=multiply(p1,p2);
    ll fac=1;
    //WHATS(p)
    for(int i=0;i<p.size();++i){
        p[i]*=fac;
        p[i]%=mod;
        fac=fac*(i+2)%mod;
    }
    vector<ll>facts(max(N,K)+1);
    vector<ll>invs(max(N,K)+1);
    facts[0]=1;
    facts[1]=1;
    invs[0]=1;
    invs[1]=1;
    for(int i=2;i<=max(N,K);++i){
        facts[i]=facts[i-1]*i%mod;
        invs[i]=invs[i-1]*mod_pow(i,mod-2)%mod;
    }
    ll answer=0;
    for(int i=1;i<=N;++i){
        if(K>=i&&(K-i)%2==1){
            answer+=p[i-1]*facts[K]%mod*invs[K-i]%mod*invs[i]%mod;
            answer%=mod;
        }
    }
    cout<<answer<<endl;
    //WHATS(p)

	return 0;
}