#include <stdio.h>
#define MOD 998244353

long long int power(long long int a, long long int b)
{
	long long int ans = 1;
	long long int k = a;
	while(b)
	{
		if(b%2==1) ans*=k, ans %=MOD;
		b/=2;
		k*=k, k%=MOD;
	}
	return ans;
}

long long int count[200010];
int main()
{
	int a,b;
	scanf("%d%d",&a,&b);
	
	long long int ans = 0;
	for(int i=1;i<=b;i++)
	{
		long long int val = power(i,a);
		val -= a*power(i-1,a-1), val %= MOD, val += MOD, val %= MOD;
		val -= power(i-1,a), val %= MOD, val += MOD, val %= MOD;
		val *= i, val %= MOD;
		ans += val, ans %= MOD;
	}
	
	for(int i=1;i<=b;i++) count[i] = power(i,a-1);
	for(int i=b;i>=1;i--) count[i] = (count[i]-count[i-1]+MOD)%MOD;
	
	long long int S = 0;
	for(int i=1;i<=b;i++)
	{
		S += (i-1)*count[i-1];
		S %= MOD;
		long long int val = S*a;
		val %= MOD;
		ans += val, ans %= MOD;
	}
	printf("%lld",ans);
}