#include <iostream>
#include <iomanip>//小数点出力用
//cout << fixed << setprecision(10) << ans;
#include <cmath>
#include <algorithm>
#include <vector>
#include <queue>
#include <stack>
#include <set>
#include <map>
#include <unordered_set>
#include <unordered_map>
using ll = unsigned long long;
using namespace std;
#define modPHash (ll)((1LL<<61)-1)
#define modP (ll)998244353
bool chkrng0idx(int pos, int sup) { return (0 <= pos && pos < sup); }
int clk4(int num) { return (num - 2) * (num % 2); }
void yn(bool tf) { cout << (tf ? "YES\n" : "NO\n"); }

unordered_map<int, int>init_fact;

ll factorial(int N) {
    int Q = N / 100'000'000;
    int R = N % 100'000'000;
    ll res = init_fact[Q * 100'000'000];
    for (int i = 1;i <= R;i++) {
        res *= (ll)(i + Q * 100'000'000);
        res %= 998244353;
    }
    return res;
}

ll modpow(ll b, ll e, ll q) {
    int i;
    ll bp = b % q;
    ll tmp = 1;
    for (i = 0; tmp <= e; i++) {
        tmp *= 2;
    }
    tmp /= 2;
    i--;
    ll ans = 1;
    for (; i >= 0; i--) {
        ans = (ll)ans * (ll)ans;
        ans %= q;
        if ((e >> i) % 2 == 1) {
            ans *= (ll)bp;
        }
        ans %= q;
        tmp /= (ll)2;
    }

    return ans;
}
int main() {
    ios::sync_with_stdio(false);
    cin.tie(nullptr);
    init_fact[0] = 1;
    init_fact[100'000'000] = 808258749;
    init_fact[200'000'000] = 117153405;
    init_fact[300'000'000] = 761699708;
    init_fact[400'000'000] = 573994984;
    init_fact[500'000'000] = 62402409;
    init_fact[600'000'000] = 511621808;
    init_fact[700'000'000] = 242726978;
    init_fact[800'000'000] = 887890124;
    init_fact[900'000'000] = 875880304;
    int N;
    cin >> N;
    int K;
    cin >> K;
    if (!(1 <= N && N <= 1'000'000'000 && 0 <= K && K <= N)) {//制約違反検出
        int tmptmp1 = 1;
        int tmptmp0 = 0;
        N = tmptmp1 / tmptmp0;//Run Time Errorさせる
        return 0;
    }
    if (N >= 998244353) {
        if (max(K, N - K) >= 998244353) {
            ll ans = 1;
            for (int i = 0;i < min(K, N - K);i++) {
                ans *= (ll)(N - i);
                ans %= 998244353;
            }
            for (int i = 1;i <= min(K, N - K);i++) {
                ans *= modpow(i, 998244353 - 2, 998244353);
                ans %= 998244353;
            }
            cout << ans;
        }
        else {
            cout << 0;
        }
    }
    else {
        ll top = factorial(N);
        ll bot = factorial(N - K) * factorial(K);
        bot %= 998244353;
        top *= modpow(bot, 998244353 - 2, 998244353);
        top %= 998244353;
        cout << top;
    }
    return 0;
}