#define MD 998244353
{
	Comb<Mint>c;
	int @n,@m,@k;
	c.expand_fact(m+1);
	Mint mm=m;
	Mint one=1;
	Mint z;
	REP(i,k+1)z=mm**n*c.ifactri[i]*c.ifactri[k-i]-z,mm+=one;
	wt(c.factri[m]*c.ifactri[m-k]*z);
}