#include <cstdio>
#include <algorithm>

using namespace std;

int main ()
{
    long long n;
    scanf ("%lld", &n);

    int rez = 0;
    for (; n > 2;)
    {
        long long cn = (n + 2) / 3;
        n = max (cn, n - 2 * cn);
        ++rez;
    }

    if (n == 2) ++rez;
    printf ("%d\n", rez);

    return 0;
}