# -*- coding: utf-8 -*-

N = int(input())
ans = 1
ans2 = 1
temp = 2
temp2 = 3
while temp <= N:
    ans += 1
    temp *= 2
while temp2 <= N:
    ans2 += 1
    temp2 *= 3

if N == 5:
    print(5)
else:
    print(min(ans*2, ans2*3))