#include <iostream>
#include <cmath>
using namespace std;
int main(){
    // a1 = 1
    // an = 2(an-1 + 1)
    // an + 2 = 2(an-1 + 2)
    // an + 2 = 3*2^(n-1)
    // an = 3*2^(n-1) - 2
    int x;
    while (cin >> x){
        cout << 3*(long long)pow(2,x-1)-2 << endl;
    }
    return 0;
}