#include<bits/stdc++.h>
using namespace std;
using ll = long long int;

const int mod = 998244353;

ll modexpo(ll x, ll n){
    ll res  = 1;
    while(n){
        if(n&1) res = res * x % mod;
        x = x * x % mod;
        n >>= 1;
    }
    return res;
}



int main(){
    ios::sync_with_stdio(false); cin.tie(0);

    int n, k;

    cin>>n>>k;

    ll ans = modexpo(n, k);
    ll temp = (n-1) * modexpo(n, k) % mod;

    ll inv2 = modexpo(2, mod-2);

    if(k % 2 == 1){
        ans += temp * inv2;
        ans %= mod;
        cout<<ans<<"\n";
        return 0;
    }

    ll kfac = 1;
    for(int i = 1; i<=k; i++) kfac = kfac * i % mod;

    ll k2fac = 1;
    for(int i = 1; i<=k/2; i++) k2fac = k2fac * i % mod;


    ll temp2 = 0;
    for(int i = 1; i<=n-1; i++){
        temp2 += modexpo(i, k/2) * modexpo(n-i, k/2);
        temp2 %= mod;
    }

    temp2 = temp2 * kfac % mod;
    temp2 = temp2 * modexpo(k2fac, 2*(mod-2)) % mod;

    temp = temp - temp2;
    if(temp < 0) temp += mod;

    ans += temp * inv2;
    ans %= mod;
    cout<<ans<<"\n";



    return 0;
}