#include <bits/stdc++.h>
using namespace std;
using ll = long long;
#define rep(i,n) for (int i=0;i<(int)(n);i++)

const int MOD=998244353;
const int MAX_N=2e5;
vector<ll> fac(MAX_N+1,1);
vector<ll> finv(MAX_N+1,1);
vector<ll> inv(MAX_N+1,1);
void comb_setup(){
  for(int i=2;i<=MAX_N;i++){
    fac.at(i)=(fac.at(i-1)*i)%MOD;
    inv.at(i)=MOD-(inv.at(MOD%i)*(MOD/i))%MOD;
    finv.at(i)=(finv.at(i-1)*inv.at(i))%MOD;
  }
}
ll comb(ll n,ll k){
  if(n<k) return 0;
  n%=MOD;
  k%=MOD;
  return fac.at(n)*(finv.at(n-k)*finv.at(k)%MOD)%MOD;
}

ll mpow(ll a,ll n){
  ll ans=1;
  while(n>0){
    if(n&1) ans=ans*a%MOD;
    a=a*a%MOD;
    n>>=1;
  }
  return ans;
}

int main(){
  comb_setup();
  ll n,m;
  cin>>n>>m;
  if(n<m){
    cout<<0<<endl;
    return 0;
  }
  ll nw=0;
  ll tmp=1;
  rep(i,m){
    nw=(nw+tmp)%MOD;
    tmp*=n-i;
    tmp%=MOD;
    tmp*=inv.at(i+1);
    tmp%=MOD;
  }
  cout<<(mpow(2,n)-nw+MOD)%MOD<<endl;
}