#include<bits/stdc++.h>
using namespace std;
const int mod=998244353;
int qpow(int a,int b){
    int c=1;
    for(;b;b>>=1){
        if(b&1)c=1ll*a*c%mod;
        a=1ll*a*a%mod;
    }
    return c;
}
int n,m,f[1001000],p[1001000],pi[1001000],im;
int main(){
    scanf("%d%d",&n,&m);im=qpow(m,mod-2);
    p[0]=pi[0]=1;
    for(int i=1;i<=n;i++)p[i]=1ll*p[i-1]*m%mod,pi[i]=1ll*pi[i-1]*im%mod;
    int ans=0;
    for(int i=1,s=0;i<=(n-1)/2;i++){
        f[i]=p[i];
        if(!(i&1))(s+=1ll*f[i/2]*pi[i]%mod)%=mod;
        (f[i]+=mod-1ll*s*p[i]%mod)%=mod;
        (ans+=1ll*f[i]*p[n-i*2]%mod)%=mod;
    }
    printf("%d",ans);
    return 0;
}