#include <iostream>
#include <cmath>
using namespace std;
int main() {
int n;
cin>>n;
long long d=pow(2, n);
cout<<d<<endl;
return 0;
}

#danglam228

#include <bits/stdc++.h>
using namespace std;
int n;
long long dem(int n) {
    if (n <= 0) return 0;
    if (n == 1) return 2;
    long long np[n + 1];
    np[1] = 2;
    np[2] = 4;
    for (int i = 3; i <= n; ++i) {
        np[i] = np[i - 1] + np[i - 2];
    }
    return np[n];
}
int main() {
    ios_base::sync_with_stdio(false);
    cin.tie(0); cout.tie(0);
    //freopen(".INP", "r", stdin);
    //freopen(".OUT", "w", stdout);
    cin >> n;
    long long res = dem(n);
    cout << res << endl;
    return 0;
}