#include <bits/stdc++.h>
using namespace std;
int main() {
  long long a[57];
  a[0] = 0;
  long long c = 0;
  int n;
  cin >> n;
  for (int i = 1; i <= 55; i++) {
    a[i] = pow(2, i);
  }
  for (int i = 1; i <= n; i++) c += a[i];
  cout << c;
}
