#include <bits/stdc++.h>
using namespace std;

typedef long long ll;
const ll mod=998244353;
const ll inv2=(mod+1)/2;
ll ksm(ll a,ll x){
	ll ret=1;
	for (;x;x>>=1,a=a*a % mod) if (x&1) ret=ret*a%mod;
	return ret;
}
ll inv(ll a){return ksm(a,mod-2);}

const int maxn=1000000;
ll fac[maxn+50];
ll ifac[maxn+50];
void prepare(){
	fac[0]=1;
	for (int i=1;i<=maxn;i++) fac[i]=fac[i-1]*i%mod;
	ifac[maxn]=inv(fac[maxn]);
	for (int i=maxn-1;i>=0;i--) ifac[i]=ifac[i+1]*(i+1)%mod;	
}
ll C(ll n,ll m){
	if (m<0 || m>n) return 0;
	return fac[n]*ifac[m]%mod*ifac[n-m]%mod;	
}

ll n,k;

int main(){
	ios_base::sync_with_stdio(false);
	prepare();
	cin >> n >> k;
	ll ans=(n+1)*ksm(n,k)%mod*inv2%mod;
	if (k%2==0){
		ll sum=0;
		for (int i=1;i<n;i++){
			sum=(sum+ksm(i,k/2)*ksm(n-i,k/2)%mod*C(k,k/2))%mod;
		}
		sum=sum*inv2%mod;
		ans=(ans+mod-sum)%mod;
	}
	cout << ans << "\n";
	return 0;	
}