#include <bits/stdc++.h>

using namespace std;

const int mod = 998244353;

long long fact[500050],inv[500050];

long long qpow(long long base,int tms)
{
	long long tmp = 1;
	while(tms)
	{
		if(tms & 1) tmp = tmp * base % mod;
		base = base * base % mod;
		tms >>= 1;
	}
	return tmp;
}

int main()
{
	int n,k;
	fact[0] = 1;
	for(int i = 1;i <= 500000; ++ i)
		fact[i] = fact[i - 1] * 1ll * i % mod;
	inv[500000] = qpow(fact[500000],mod - 2);
	inv[0] = 1;
	for(int i = 499999;i >= 1; -- i)
		inv[i] = inv[i + 1] * 1ll * (i + 1) % mod;
	scanf("%d%d",&n,&k);
	long long ans = 0;
	for(int i = n;i <= k; ++ i) ans = (ans + fact[k - 1] * inv[k - i] % mod * inv[i - 1] % mod) % mod;
	printf("%lld\n",(ans) % mod);
	return 0;
}