#pragma GCC optimize("O3")
#pragma GCC optimize("Ofast")
#pragma GCC optimize("unroll-loops")
#pragma GCC target("avx,avx2")
#include <bits/stdc++.h>
#define all(x) x.begin(),x.end()
#define long long long
#define INF 1000000001
#define LNF 10000000011000000001
#define MOD 998244353
using namespace std;

long power(int a, int b)
{
    if(b == 0)
        return 1;
    if(b == 1)
        return a;
    
    long c = power(a,b/2);
    c = c*c%MOD;

    if(b&1)
        return c*a%MOD;
    return c;
}
long modinv(int x)
{
    return power(x,MOD-2);
}
int main() {
    ios_base::sync_with_stdio(0);
    cin.tie(0);

    int n,k;
    cin >> n >> k;

    k = min(k,n-k);

    long top = 1;
    long down = 1;
    for(int i = 0; i<k; i++)
        top = top*(n-i)%MOD;
    for(int i = 1; i<=k; i++)
        down = down*i%MOD;

    cout << top*modinv(down)%MOD << endl;
    return 0;
}