#include<bits/stdc++.h>
#define int long long
#define ffor(i,a,b) for(int i=(a);i<=(b);i++)
#define roff(i,a,b) for(int i=(a);i>=(b);i--)
using namespace std;
const int MAXN=1e6+10,MOD=998244353;
int n,m,dp[MAXN],pw[MAXN],inv[MAXN],pre[MAXN],ans;
int qpow(int base,int p) {
	int ans=1;
	while(p) {
		if(p&1) ans=ans*base%MOD;
		base=base*base%MOD,p>>=1;
	}
	return ans;
}
signed main() {
	ios::sync_with_stdio(false),cin.tie(0),cout.tie(0);
	cin>>n>>m;
	pw[0]=1;
	ffor(i,1,n) pw[i]=pw[i-1]*m%MOD;
	inv[n]=qpow(pw[n],MOD-2);
	roff(i,n-1,0) inv[i]=inv[i+1]*m%MOD;
	dp[1]=m,pre[1]=inv[1];
	ffor(i,2,n) {
		//<=i/2
		dp[i]=(pw[i]-pre[i/2]*pw[i])%MOD;
		if(2*i<=n) pre[i]=(pre[i-1]+dp[i]*inv[2*i])%MOD;
	}
	ffor(i,1,n/2) {
		int rst=n-2*i;
		if(rst>0) ans=(ans+dp[i]*pw[rst])%MOD;	
	}
	cout<<(ans%MOD+MOD)%MOD;
	return 0;
}