#include<stdio.h>
long long int modpow(long long int a, long long int n, long long int p)
{
	long long int res = 1;
	for (; n > 0; n /= 2, a = a * a % p)
		if (n % 2 > 0)
			res = res * a % p;
	return res;
}
int main()
{
	long long int fact7[102] = { 1,295201906,160030060,957629942,545208507,213689172,760025067,939830261,506268060,39806322,808258749,440133909,686156489,741797144,390377694,12629586,544711799,104121967,495867250,421290700,117153405,57084755,202713771,675932866,79781699,956276337,652678397,35212756,655645460,468129309,761699708,533047427,287671032,206068022,50865043,144980423,111276893,259415897,444094191,593907889,573994984,892454686,566073550,128761001,888483202,251718753,548033568,428105027,742756734,546182474,62402409,102052166,826426395,159186619,926316039,176055335,51568171,414163604,604947226,681666415,511621808,924112080,265769800,955559118,763148293,472709375,19536133,860830935,290471030,851685235,242726978,169855231,612759169,599797734,961628039,953297493,62806842,37844313,909741023,689361523,887890124,380694152,669317759,367270918,806951470,843736533,377403437,945260111,786127243,80918046,875880304,364983542,623250998,598764068,804930040,24257676,214821357,791011898,954947696,183092975,0 };
	long long int n, k;
	scanf("%lld %lld", &n, &k);
	if (k > n - k)
		k = n - k;
	const long long int p = 998244353;
	long long int a, b, c, i;
	long long int e = 10000000;
	if (n >= p)
	{
		if (n - k < p)
			printf("0\n");
		else
		{
			a = b = 1;
			for (i = 0; i < k; i++)
			{
				a = a * (n - i) % p;
				b = b * (i + 1) % p;
			}
			printf("%lld\n", a * modpow(b, p - 2, p) % p);
		}
	}
	else
	{
		a = fact7[n / e];
		for (i = n / e * e + 1; i <= n; i++)
			a = a * i % p;
		b = fact7[k / e];
		for (i = k / e * e + 1; i <= k; i++)
			b = b * i % p;
		c = fact7[(n - k) / e];
		for (i = (n - k) / e * e + 1; i <= n - k; i++)
			c = c * i % p;
		printf("%lld\n", a * modpow(b * c % p, p - 2, p) % p);
	}
	return 0;
}