#include <iostream>

using namespace std;

constexpr int Z = 998244353;

int bexp(int a, int n) {
    if (n == 0) {
        return 1;
    }
    if (n % 2 == 1) {
        return 1ll * a * bexp(a, n - 1) % Z;
    }
    int t = bexp(a, n / 2);
    return 1ll * t * t % Z;
}

int main() {
    int n, k;
    cin >> n >> k;

    int inv[n+k+1];
    for (int i = 0; i <= n + k; i++) {
        inv[i] = i <= 1 ? i : 1ll * (Z - Z / i) * inv[Z%i] % Z;
    }

    int ifac[n+1];
    for (int i = 0; i <= n; i++) {
        ifac[i] = i == 0 ? 1 : 1ll * inv[i] * ifac[i-1] % Z;
    }

    int ans = 0;
    for (int i = 0; i <= n; i++) {
        int t = 1ll * ifac[i] * ifac[n-i] % Z * bexp(n - i, n + k) % Z;
        ans = (0ll + ans + (i % 2 == 0 ? 1 : -1) * t + Z) % Z;
    }

    ans = 1ll * ans * bexp(inv[n], k) % Z;
    for (int i = 1; i <= n; i++) {
        ans = 1ll * ans * inv[k+i] % Z * i % Z;
    }

    cout << ans << endl;

    return 0;
}