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


#define ll long long


const ll MOD = 998244353;


ll binpow(ll a, ll p) {
    if (p == 0) {
        return 1;
    }

    if (p % 2 == 1) {
        return (a * (binpow((a * a) % MOD, p / 2)) % MOD) % MOD;
    } else {
        return binpow((a * a) % MOD, p / 2) % MOD;
    }
}


int main() {
    ios_base::sync_with_stdio(false);
    cin.tie(nullptr);
 
    // freopen("input.txt", "r", stdin);
    // freopen("output.txt", "w", stdout);

    ll n;
    cin >> n;
    vector<ll> fi(n);
    fi[0] = 1, fi[1] = 1;
    for (int i = 2; i < n; ++i) {
        fi[i] = (fi[i - 1] + fi[i - 2]) % MOD;
    }

    cout << (fi[n - 1] * binpow(2, n * (MOD - 2))) % MOD << '\n';

    return 0;
}