#include <iostream>

using namespace std;

int n, nr = 0, v[15];

void ch()
{
    int x = 1;
    while(v[x] == v[n-x+1] && x >= n-x+1)
        ++x;
    if(x > n-x+1)
        nr += 1;
    else
        nr += 2;
}

void bk(int x)
{
    if(x > n)
        ch();
    else
        for(int i = v[x-1]; i < 3; ++i)
        {
            v[x] = i;
            bk(x+1);
        }
}

int main()
{
    v[0] = 1;
    cin >> n;
    --n;
    bk(1);
    cout << nr;
}