#include<bits/stdc++.h>
#define ll long long
const int mod = 998244353;
const int N = 1e6+10;

using namespace std;

ll fac[N+10],rfac[N+10];
int n,k;
inline ll fpm(ll x,ll y){
	ll s=1;
	while(y){
		if(y&1) s=s*x%mod;
		y>>=1; x=x*x%mod;
	}
	return s;
}

void init(){
	fac[0]=1ll;
	for(int i=1; i<=N; ++i) fac[i]=fac[i-1]*i%mod;
	rfac[N]=fpm(fac[N],mod-2);
	for(int i=N-1; i>=0; --i) rfac[i]=rfac[i+1]*(i+1)%mod;
}

ll c(int x,int y){
	if(x<y) return 0;if(x<0) return 0; if(y<0) return 0;
	return fac[x]*rfac[y]%mod*rfac[x-y]%mod;
}

ll rv(int x) { return fpm(x,mod-2);}
int main(){
	//freopen("e.in","r",stdin);
	//freopen("e.out","w",stdout);
	init();
	scanf("%d%d",&n,&k);
	long long ans=0;
	for(int i=n; i<=k; ++i){
		int r=i,b=k-i;
		int t=max(r-n+1,0);
		ans+=c(r+b,b)-c(r+b,b-t);
		ans=(ans%mod+mod)%mod;
	}
	printf("%lld\n",ans);
}