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

using ll = long long;
using pii = pair<int, int>;
using pll = pair<ll, ll>;
using vi = vector<int>;
using vl = vector<ll>;
#define rep3(i, a, b, c) for (ll i = (a); i < (b); i += (c))
#define rep2(i, a, b) rep3(i, a, b, 1)
#define rep1(i, n) rep2(i, 0, n)
#define rep0(n) rep1(aaaaa, n)
#define ov4(a, b, c, d, name, ...) name
#define rep(...) ov4(__VA_ARGS__, rep3, rep2, rep1, rep0)(__VA_ARGS__)
#define per(i, a, b) for (ll i = (a) - 1; i >= (b); i--)
#define fore(e, v) for (auto &&e : v)
#define all(a) begin(a), end(a)
#define sz(a) (int)(size(a))
#define lb(v, x) (lower_bound(all(v), x) - begin(v))
#define eb emplace_back

template <typename T, typename S> bool chmin(T &a, const S &b) {
  return a > b ? a = b, 1 : 0;
}
template <typename T, typename S> bool chmax(T &a, const S &b) {
  return a < b ? a = b, 1 : 0;
}
const int INF = 1e9 + 100;
const ll INFL = 3e18 + 100;
#define i128 __int128_t
struct _ {
  _() { cin.tie(0)->sync_with_stdio(0), cout.tie(0); }
} __;

const int MOD = 998244353;

ll extGCD(ll a, ll b, ll &x, ll &y) {
  if (b == 0) {
    x = 1, y = 0;
    return a;
  }
  ll d = extGCD(b, a % b, y, x);
  y = y - a / b * x;
  return d;
}
ll modinv(ll a, ll m) {
  ll x = 0, y = 0, d = extGCD(a, m, x, y);
  if (d != 1) {
    return -1;
  }
  return x;
}

int main() {
  ll N, K;
  cin >> N >> K;
  ll L = N - K;
  const vl fact = {
      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, 613786113};
  if (N >= MOD && L < MOD && K < MOD) {
    cout << "0\n";
  } else {
    auto factorial = [&](ll n) {
      const ll block = 10'000'000;
      ll fn = fact[n / block];
      rep(i, n - n % block + 1, n + 1) {
        if (i != MOD)
          fn = fn * i % MOD;
      }
      return fn;
    };
    ll fN = factorial(N), fK = factorial(K), fL = factorial(L);
    ll ans = fN * modinv(fK, MOD) % MOD * modinv(fL, MOD) % MOD;
    if (ans < 0)
      ans += MOD;
    cout << ans << '\n';
  }
}