#include<bits/stdc++.h>
#define ll long long
#define pii pair<int,int>
using namespace std;
const ll mod = 998244353;
ll dp[200010];
ll sum[200010];
ll fpow(ll x,ll b){
    ll res=1;
    for(;b;b>>=1){
        if(b&1) res=res*x%mod;
        x=x*x%mod;
    }
    return res;
}
int main(){
    ll n;
    cin>>n;
    sum[0]=1;
    sum[1]=1;
    for(ll i=1;i<=n;i++){
        sum[i+1]+=sum[i];
        sum[i+2]+=sum[i];
        sum[i+1]%=mod;
        sum[i+2]%=mod;
    }
    ll f=fpow(2,n);
    f%=mod;
    ll c=fpow(f,mod-2);
    cout<<sum[n]*c%mod<<'\n';
}