import sys 
import os
import collections
import math

def prime_table(n):
  list = [True for _ in xrange(n + 1)] 
  i = 2 
  while i * i <= n:
    if list[i]:
      j = i + i 
      while j <= n:
        list[j] = False
        j += i
    i += 1

  table = [i for i in xrange(n + 1) if list[i] and i >= 2]
  return table

def may_mel(p):
  print len(format(int(math.pow(2, p))-1, "b"))

may_mel(int(raw_input()))