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

const int M = 1e6+5;
const int mod = 998244353;

inline int ksm(int x, int p) {
    if (p == 0) return 1;
    if (p == 1) return x;
    int t = ksm(x, p >> 1);
    if (p & 1) return t * t % mod * x % mod;
    return t * t % mod;
}

inline int inv(int x) {
    return ksm(x % mod, mod - 2);
}
int fac[M];
inline void pre() {
    fac[0] = 1;
    for (int i = 1; i < M; i++) fac[i] = fac[i - 1] * i % mod;
}

inline int C(int n, int m) {
    if (n < m) return 0;
    return fac[n] * inv(fac[m]) % mod * inv(fac[n - m]) % mod;
}

signed main() {
    ios::sync_with_stdio(0);
    cin.tie(0), cout.tie(0);
    int n, k;
    pre(); cin >> n >> k;
    int ans = (n + 1) * ksm(n, k) % mod * inv(2) % mod;
    if (k & 1) return cout << ans << endl, 0;
    int res = 0;
    for (int i = 1; i <= n - 1; i++) (res += ksm(i, k / 2) * ksm(n - i, k / 2) % mod) %= mod;
    res = res * C(k, k / 2) % mod;
    ans = ((ans - res * inv(2) % mod) % mod + mod) % mod;
    cout << ans << endl;
    return 0;
}