#include <stdio.h>
unsigned int sum (int k)
{
    int i;
    unsigned int xn1, xn2, xn3, s, o;
    xn1 = 2;
    xn2 = 9;
        s = 9;
        o = 1;
    for (i=2; i<=k;i++)
    {
        o *= 4;
        xn3 = 5 * xn2 - 6 * xn1 + o;
        s += xn3;
        xn1 = xn2;
        xn2 = xn3;
    }
    return(s);
}
int main(void)
{
    int n;
    unsigned int res;
    scanf_s("%d", &n);
    res = sum(n);
    printf("%d", res);
    return(0);
}