#include <bits/stdc++.h>

const int N = 30;
int a[N] = {2};
using namespace std;

int main() {
    int n;
    cin >> n;
    for (int i = 1; i <= n; ++i) a[i] = a[i - 1] + pow(2, i - 1);
    printf("%d", a[n]);
    return 0;
}