#include <bits/stdc++.h>
using namespace std;
int main() {
  long long int n;
  cin >> n;
  long long int sum = 0;
  int i = 1;
  long long int prefum = 0;
  while (i <= n) {
    prefum = sum;
    sum = prefum + pow(2, i);
    i++;
  }
  cout << sum << endl;
}
