#include <iostream>
#include <cstdio>
#include <cmath>

using namespace std;

long long N;

int solve(long long nr) {
    if(nr == 1) {
        return 0;
    }

    if(nr > 1 && nr < 4) {
        return 1;
    }

    long long group = nr / 3 + (nr % 3 != 0);
    long long remain = nr - 2 * group;

    return solve(max(remain, group)) + 1;
}

int main() {
    cin >> N;

    cout << solve(N) << '\n';

    return 0;
}