#include <bits/stdc++.h>

using namespace std;

void __print(int x) {cout << x;}
void __print(long x) {cout << x;}
void __print(long long x) {cout << x;}
void __print(unsigned x) {cout << x;}
void __print(unsigned long x) {cout << x;}
void __print(unsigned long long x) {cout << x;}
void __print(float x) {cout << x;}
void __print(double x) {cout << x;}
void __print(long double x) {cout << x;}
void __print(char x) {cout << '\'' << x << '\'';}
void __print(const char *x) {cout << '\"' << x << '\"';}
void __print(const string &x) {cout << '\"' << x << '\"';}
void __print(bool x) {cout << (x ? "true" : "false");}
template<typename T, typename V>
void __print(const pair<T, V> &x) {cout << '{'; __print(x.first); cout << ','; __print(x.second); cout << '}';}
template<typename T>
void __print(const T &x) {int f = 0; cout << '{'; for (auto &i: x) cout << (f++ ? "," : ""), __print(i); cout << "}";}
void _print() {cout << "]\n";}
template <typename T, typename... V>
void _print(T t, V... v) {__print(t); if (sizeof...(v)) cout << ", "; _print(v...);}
#ifndef ONLINE_JUDGE
#define debug(x...) cout << "[" << #x << "] = ["; _print(x)
#else
#define debug(x...)
#endif
#define ll long long
#define all(x) (x).begin(), (x).end()
typedef vector<int> vi;
typedef vector<ll> vll;
typedef pair<int, int> pii;
typedef pair<ll, ll> pll;
const int d4i[4]={-1, 0, 1, 0}, d4j[4]={0, 1, 0, -1};
const int d8i[8]={-1, -1, 0, 1, 1, 1, 0, -1}, d8j[8]={0, 1, 1, 1, 0, -1, -1, -1};

const ll MOD = 998244353;
ll powmod(ll base, ll exponent)
{
    if (exponent < 0)
        exponent += MOD - 1;
    ll ans = 1;
    while (exponent) {
        if (exponent&1)
            ans = (ans * base) % MOD;
        base = (base * base) % MOD;
        exponent /= 2;
    }
    return ans;
}

void solve() {
    ll n;
    cin >> n;

    ll a = 1, b = 1;
    for (int i = 3; i <= n; ++i) {
        ll tmp = (a + b) % MOD;
        a = b;
        b = tmp;
    }
    
    ll ans = (b * powmod(2, -n)) % MOD;
    cout << ans;
}

int main() {
    ios::sync_with_stdio(0); cin.tie(0);
    // int t;
    // cin >> t;
    // while (t--)
        solve();
       
    return 0;
}
