#define MD 998244353

{
	Comb<Mint> c;
	int @n,@m,@k;
	Mint z;
	Mint invm=Mint(1)/Mint(m);
	Mint v=1;
	rep(i,k+1){
		z=v**n*c.ifac(i)*c.ifac(k-i)-z;
		v+=invm;
	}
	wt(z*c.fac(m)*c.ifac(m-k)*Mint(m)**n);
}