#include<iostream>
using namespace std;

int main()
{
    int n;
    while (cin >> n, n != 0)
    {
        int m=1;
        for (int i = 1;i < n;++i)
        {
            m = (m + 1) * 2;
        }
        cout << m << endl;
    }
    return 0;
}