#include <bits/stdc++.h>
using namespace std;
typedef long long ll;
#define pii pair<int, int>
#define vi vector<int>
//const int mod = 1e9 + 7;
const int mod = 998244353;
const int inf = 1e9;
ll dp[200005];

ll exgcd(ll a, ll b, ll &x, ll &y) {
    if (b == 0) {
        x = 1, y = 0;
        return a;
    }
    ll d = exgcd(b, a % b, x, y);
    ll temp = x;
    x = y;
    y = temp - a / b * y;
    return d;
}

ll getInv(ll a, ll m) {
    ll x, y;
    exgcd(a, m, x, y);
    return (x % m + m) % m;
}

int main() {
    ios::sync_with_stdio(false); cin.tie(nullptr);
    int n;
    cin >> n;
    dp[1] = 1, dp[2] = 1;
    for (int i = 3; i <= n; i++) dp[i] = (dp[i - 1] + dp[i - 2]) % mod;
    ll two = getInv(2, mod);
    ll ans = dp[n];
    for (int i = 1; i <= n; i++) {
        ans = ans * two % mod;
    }
    cout << ans << "\n";
}