#include <stdio.h>
 int prob(int n)
{
     unsigned int i,o;
 int xnprev,xnnext;
xnprev = xnnext = 1;
o = 2;
     for (i = 1; i <= n; i++)
     {
         xnnext = 3 * xnprev + 4 * o;
         xnprev = xnnext;
         o *= 2;
     }
 return(xnnext);
}
int main(void)
{
int h,k;
    scanf("%d", &k);
        h = prob(k);
        printf("%d", h);
    return 0;
}