#include <bits/stdc++.h>
#include <atcoder/modint>

using namespace std;
using ll = long long;
using mint = atcoder::modint998244353;

constexpr ll MOD = 998244353LL;
const ll fac[] = {1, 295201906, 160030060, 957629942, 545208507, 213689172, 760025067, 939830261, 506268060, 39806322, 808258749, 440133909, 686156489, 741797144, 390377694, 12629586, 544711799, 104121967, 495867250, 421290700, 117153405, 57084755, 202713771, 675932866, 79781699, 956276337, 652678397, 35212756, 655645460, 468129309, 761699708, 533047427, 287671032, 206068022, 50865043, 144980423, 111276893, 259415897, 444094191, 593907889, 573994984, 892454686, 566073550, 128761001, 888483202, 251718753, 548033568, 428105027, 742756734, 546182474, 62402409, 102052166, 826426395, 159186619, 926316039, 176055335, 51568171, 414163604, 604947226, 681666415, 511621808, 924112080, 265769800, 955559118, 763148293, 472709375, 19536133, 860830935, 290471030, 851685235, 242726978, 169855231, 612759169, 599797734, 961628039, 953297493, 62806842, 37844313, 909741023, 689361523, 887890124, 380694152, 669317759, 367270918, 806951470, 843736533, 377403437, 945260111, 786127243, 80918046, 875880304, 364983542, 623250998, 598764068, 804930040, 24257676, 214821357, 791011898, 954947696, 183092975, 0};

ll f(ll n) {
    ll _n = n / 10000000 * 10000000;
    ll res = fac[_n];

    for (int i = _n + 1; i <= n; i++) {
        res *= i;
        res %= MOD;
    }
    return res;
}

int main() {
    ll N, K; cin >> N >> K;
    K = min(K, N - K);

    ll num = 1LL;
    ll div = 1LL;
    if (K <= 100000000) {
        for (int i = 0; i < K; i++) {
            num = num * (N - i) % MOD;
            div = div * (K - i) % MOD;
        }
    } else {
        num = f(N);
        div = f(N - K) * f(K) % MOD;
    }

    cout << (mint(num) / mint(div)).val() << "\n";
}