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

// combination MOD
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(int n,int k){
  if(n<k) return 0;
  return fac.at(n)*(finv.at(n-k)*finv.at(k)%MOD)%MOD;
}

int main(){
  comb_setup();
  ll a,b;
  cin>>a>>b;
  cout<<comb(a+b-2,a-1)<<endl;
}