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

const int mod = 998244353;
const int inv2 = (mod + 1) / 2;
const int N = 1e6 + 65;
int n, k;
int fac[N], invfac[N];

int ksm(int a, int b) {
    int ret = 1;
    while (b) {
        if (b & 1)
            ret = 1ll * ret * a % mod;
        b >>= 1, a = 1ll * a * a % mod;
    }
    return ret;
}

int C(int n, int m) {
    return 1ll * fac[n] * invfac[m] % mod * invfac[n - m] % mod;
}

int main() {
    cin >> n >> k;
    fac[0] = invfac[0] = 1;
    for (int i = 1; i < N; i++) fac[i] = 1ll * fac[i - 1] * i % mod;
    invfac[N - 1] = ksm(fac[N - 1], mod - 2);
    for (int i = N - 2; i >= 1; i--) invfac[i] = 1ll * invfac[i + 1] * (i + 1) % mod;

    if (k & 1) {
        cout << 1ll * (n + 1) * inv2 % mod * ksm(n, k) % mod << endl;
    } else {
        int ans = 1ll * (n + 1) * inv2 % mod;
        int res = 0;
        for (int i = 1; i < n; i++) {
            int p = 1ll * ksm(i, k / 2) * ksm(n - i, k / 2) % mod * C(k, k / 2) % mod;
            res = (res + 1ll * p) % mod;
        }
        res = 1ll * res * inv2 % mod;
        res = 1ll * res * ksm(ksm(n, k), mod - 2) % mod;
        ans -= res;
        ans = (ans % mod + mod) % mod;
        ans = 1ll * ans * ksm(n, k) % mod;
        cout << ans << "\n";
    }

    return 0;
}