#include <bits/stdc++.h>
using namespace std;
const int N = 1e6 + 10;
const int p = 998244353;
const int inv2 = (p + 1) >> 1;
int n, m, fac[N], finv[N], inv[N];
inline int Qpow(int x, int y = p - 2) {
    int ans = 1;
    for (; y; y >>= 1, x = 1ll * x * x % p) 
        if (y & 1) ans = 1ll * ans * x % p;
    return ans;
}
inline int C(int x, int y) {
    if (x < 0 || x < y) return 0;
    return 1ll * fac[x] * finv[y] % p * finv[x - y] % p;
}
int main() {
    fac[0] = 1; for (int i = 1; i < N; ++i) fac[i] = 1ll * fac[i - 1] * i % p;
    inv[0] = inv[1] = 1; for (int i = 2; i < N; ++i) inv[i] = 1ll * inv[p % i] * (p - p / i) % p;
    finv[0] = 1; for (int i = 1; i < N; ++i) finv[i] = 1ll * finv[i - 1] * inv[i] % p;
    scanf("%d%d", &n, &m);
    int ans = 1ll * Qpow(n, m) * (n + 1) % p * inv2 % p;
    if (m % 2 == 0) {
        int u = m / 2;
        int sm = 0;
        int mid = 1ll * (n + 1) * inv2 % p;
        for (int i = 1; i <= n; ++i) {
            sm = (sm + 1ll * (i - mid) * C(i + u - 1, u - 1) % p * C(n - i + u - 1, u)) % p;
        }
        ans = (ans + 1ll * C(m, u) * sm) % p;
        if (ans < 0) ans += p;
    }
    printf("%d\n", ans);
    return 0;
}