#include <bits/stdc++.h>
using namespace std ;
typedef long long ll;
const int N=1919810,mod=998244353;
ll n,m;
char s[N];

ll ksm(ll x,ll p){
    ll sum=1,item=x;
    while(p){
        if(p&1) sum=sum*item%mod;
        p>>=1;
        item=item*item%mod;
    }
    return sum;
}


int main()
{
    cin>>n>>m;
    if(n==1){
        cout<<m*m%mod<<endl;
    }else{
        ll ans=ksm(m,n);
        ans*=(m-1);
        ans%=mod;
        ans%=mod;
        ans-=ksm(m,n);
        ans+=mod;
        ans%=mod;

        cout<<ans<<endl;
    }

}