#include <bits/stdc++.h>
using namespace std;
const long double PI = 3.141592653589793238L;
int main() {
  long long n, b = 2, res = 0;
  cin >> n;
  for (int i = 0; i < n; i++, b = b << 1) {
    res += b;
  }
  cout << res << endl;
  return 0;
}
