#include<bits/stdc++.h>
#include<atcoder/all>
using namespace std;
using namespace atcoder;
typedef long long int ll;
typedef long double ld;
typedef vector<int> vi;
typedef vector<ll> vl;
typedef vector<vl> vvl;
typedef vector<vvl> vvvl;
typedef vector<vvvl> vvvvl;
typedef vector<bool> vb;
typedef vector<vb> vvb;
typedef vector<vvb> vvvb;
typedef vector<vvvb> vvvvb;
typedef pair<ll,ll> pl;
typedef pair<ll,pl> ppl;
typedef pair<ll,ppl> pppl;
typedef pair<ll,pppl> pppppl;
#define rep(i,a,b) for(int i=(a);i<(b);i++)
#define rrep(i,a,b) for(int i=(b)-1;i>=(a);i--)
#define all(a) begin(a),end(a)
#define sz(a) (int)(a).size()
#define F first
#define S second
#define bs(A,x) binary_search(all(A),x)
#define lb(A,x) (ll)(lower_bound(all(A),x)-A.begin())
#define ub(A,x) (ll)(upper_bound(all(A),x)-A.begin())
#define cou(A,x) (ll)(upper_bound(all(A),x)-lower_bound(all(A),x))
template<typename T>using min_priority_queue=priority_queue<T,vector<T>,greater<T>>;
template<class T>bool chmax(T&a,T b){if(a<b){a=b;return 1;}return 0;}
template<class T>bool chmin(T&a,T b){if(b<a){a=b;return 1;}return 0;}
//*
using mint=modint998244353;
const ll mod=998244353;
//*/
/*
using mint=modint1000000007;
const ll mod=1000000007;
//*/
//using mint=modint;
//*
typedef vector<mint> vm;
typedef vector<vm> vvm;
typedef vector<vvm> vvvm;
typedef vector<vvvm> vvvvm;
ostream&operator<<(ostream&os,mint a){os<<a.val();return os;}
istream&operator>>(istream&is,mint&a){int x;is>>x;a=mint(x);return is;}
//*/
template<typename T1,typename T2>ostream&operator<<(ostream&os,pair<T1,T2>p){os<<p.F<<" "<<p.S;return os;}
template<typename T1,typename T2>istream&operator>>(istream&is,pair<T1,T2>&p){is>>p.F>>p.S;return is;}
template<typename T>ostream&operator<<(ostream&os,vector<T>v){rep(i,0,sz(v))os<<v[i]<<(i+1!=sz(v)?" ":"");return os;}
template<typename T>istream&operator>>(istream&is,vector<T>&v){for(T&in:v)is>>in;return is;}
template<typename T>
vector<T>inv(const vector<T>&f){
    assert(f[0].val());
    vector<T>g{f[0].inv()};
    while(g.size()<f.size()){
      vector<T>x(f.begin(),f.begin()+min(f.size(),2*g.size()));
      x=convolution(x,convolution(g,g));
      g.resize(2*g.size());
      for(int i=g.size()/2;i<min(x.size(),g.size());i++)g[i]-=x[i];
    }
    return {g.begin(),g.begin()+f.size()};
}
template<typename T>
pair<vector<T>,vector<T>>div(vector<T>f,const vector<T>&g){
    if(f.size()<g.size())return make_pair(vector<T>(0),f);
    reverse(f.begin(),f.end());
    vector<T>h=g;
    reverse(h.begin(),h.end());
    while(h.size()+g.size()<=f.size())h.emplace_back(0);
    vector<T>q=convolution(f,inv(h));
    q.resize(f.size()-g.size()+1);
    reverse(q.begin(),q.end());
    auto r=convolution(g,q);
    reverse(f.begin(),f.end());
    for(int i=0;i<f.size();i++)r[i]=f[i]-r[i];
    while(!r.empty()&&r.back()==T(0))r.erase(r.end()-1);
    return make_pair(q,r);
}
template<typename T>
vector<T>multipoint_evaluation(vector<T>f,vector<T>p){
    int N=p.size(),n=1;
    while(n<N)n*=2;
    vector<vector<T>>seg(2*n,vector<T>(1,1));
    for(int i=0;i<N;i++)seg[i+n]=vector<T>{-p[i],1};
    for(int i=n-1;i;i--)seg[i]=convolution(seg[2*i],seg[2*i+1]);
    seg[1]=div(f,seg[1]).second;
    for(int i=1;i<n;i++)seg[2*i]=div(seg[i],seg[2*i]).second,seg[2*i+1]=div(seg[i],seg[2*i+1]).second;
    vector<T>ans(N);
    for(int i=0;i<N;i++)if(!seg[i+n].empty())ans[i]=seg[i+n][0];
    return ans;
}
mint factorial(long long N){
    assert(N>=0);
    if(!N)return 1;
    int n=sqrtl(N);
    mint ans=1;
    while(n*n>N)n--;
    while(N>n*n)ans*=N--;
    queue<vector<mint>>que;
    for(int i=1;i<=n;i++)que.emplace(vector<mint>{i,1});
    while(que.size()>1){
        auto u=que.front();que.pop();
        auto v=que.front();que.pop();
        que.emplace(convolution(u,v));
    }
    vector<mint>p(n);
    for(int i=0;i<n;i++)p[i]=(long long)i*n;
    auto me=multipoint_evaluation(que.front(),p);
    for(auto x:me)ans*=x;
    return ans;
}
int main(){
  cin.tie(0)->sync_with_stdio(0);
  cin.exceptions(cin.failbit);
  ll N,K;cin>>N>>K;
  chmin(K,N-K);
  if(N>=mod){
  	if(N-K<mod){cout<<0<<endl;return 0;}
  	mint ans=1;
  	rep(i,0,K)ans*=N-i,ans/=i+1;
  	cout<<ans.val()<<endl;
  	return 0;
  }
  mint a=factorial(N),b=factorial(K),c=factorial(N-K);
  cout<<(a/b/c).val()<<endl;
  return 0;
}