#include <bits/stdc++.h>
using namespace std;

#define rep(i,a,b) for (int i = a; i < b; i++)
#define trav(a,b) for (auto a : b)
#define lld long long
using i64 = long long;
#define all(x) begin(x),end(x)
const lld MOD=998244353;

lld ModPow(lld base, lld exp){
	if(exp==0)return 1;
	if(exp%2==1)return (base*ModPow(base,exp-1))%MOD;
	lld a=ModPow(base,exp/2);
	return (a*a)%MOD;
}

void solve() {
	lld n,m;
	cin>>n>>m;
	lld ans=ModPow(n,m-1)*ModPow(m,n-1);
	ans%=MOD;
	cout<<ans<<"\n";
}

signed main() {
	ios::sync_with_stdio(0);
	cin.tie(0);
	int tt = 1;
	//~ cin >> tt;
	while (tt--) solve();
	return 0;
}