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

const int N=2e6+7;
const int mod=998244353;
int n,m;
int dp[N],sum[N];
int f[N],rf[N];
int modpow(int u,int v){
    int ans=1, t=u;
    while (v){
        if (v&1) ans=ans*t%mod;
        t=t*t%mod, v>>=1;
    }
    return ans;
}
signed main(){
    ios::sync_with_stdio(false);
    cin.tie(0), cout.tie(0);
    cin>>n>>m;
    f[0]=rf[0]=1;
    int rm=modpow(m,mod-2);
    for (int i=1;i<N;++i) f[i]=f[i-1]*m%mod, rf[i]=rf[i-1]*rm%mod;
    for (int i=1;i<=n;++i){
        dp[i]=f[i]*(mod+1-sum[i/2])%mod;
        sum[i]=(sum[i-1]+dp[i]*rf[2*i])%mod;
    }
    int ans=0;
    for (int i=1;i<=(n-1)/2;++i){
        ans=(ans+dp[i]*f[n-i*2])%mod;
    }
    cout<<ans;
}