import java.io.*;
import java.util.*;

public class B_FewQuestions {
    private static final BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
    private static StringTokenizer st;

    private static long readLong() throws IOException {
        while (st == null || !st.hasMoreTokens()) st = new StringTokenizer(br.readLine());
        return Long.parseLong(st.nextToken());
    }

    public static void main(String[] args) throws IOException {
        long A = readLong();

        if (A == 5) {
            System.out.println(5);
        } else {
            long min = Math.min(2 * (int) (Math.ceil(Math.log(A) / Math.log(2))),
                    3 * (int) (Math.ceil(Math.log(A) / Math.log(3))));
            System.out.println(min);
        }
    }
}