#include "bits/stdc++.h"

using namespace std;

using lint = int64_t;
const int mod = 998244353;
const int lim = 1e6 + 10;

lint power(lint x, lint n){
    x %= mod;
    lint res = 1;
    for(;n;n>>=1){
        if(n&1) res = res * x % mod;
        x = x * x % mod;
    }
    return res;
}

lint fac[lim], ifac[lim];

void prep(){
    fac[0] = 1;
    for(int i=1;i<lim;i++) fac[i] = (fac[i-1] * i) % mod;
    ifac[lim-1] = power(fac[lim-1], mod - 2);
    for(int i=lim-2;i>=0;i--) ifac[i] = (ifac[i+1] * (i + 1)) % mod;
}

int main() {
    cin.tie(nullptr)->sync_with_stdio(false);
    prep();
    lint n, k;
    cin>>n>>k;
    lint ans = power(n, k) * (n + 1) % mod * power(2, mod - 2) % mod;
    if(k&1){
        cout<<ans<<"\n";
    }
    else{
        lint cnt = 0;
        for(int i=1;i<=n;i++){
            lint cur = (n + 1 - i) % mod * ( (power(i, k/2) - power(i - 1, k/2) + mod) * power(n - i + 1, k/2) % mod - 
                (power(n - i + 1, k/2) - power(n - i, k/2) + mod) * power(i, k/2) % mod + mod) % mod;
            cnt = (cnt + cur) % mod;
        }
        cnt = cnt * fac[k] % mod * ifac[k/2] % mod * ifac[k/2] % mod * power(2, mod - 2) % mod;
        ans = (ans - cnt + mod) % mod;
        cout<<ans<<"\n";
    }
    return 0;
}