package main

import . "fmt"
import . "math/big"

func main() {
	var n,k int64
	Scan(&n,&k)
	
	const Mod = 998244353
	
	d := new(Int).Exp(NewInt(k),NewInt(n),NewInt(Mod))
	ans := d.ModInverse(d, NewInt(Mod)).Int64()
	ans = ans*k%Mod*n%Mod*(k-1)%Mod
	Println(ans)
}