#include <bits/stdc++.h>
using namespace std;
int main() {
  long long int dp[56];
  int n;
  cin >> n;
  dp[0] = 0;
  for (int i = 1; i <= n; i++) {
    dp[i] = dp[i - 1] + pow(2, i);
  }
  cout << dp[n];
}
