# -*- coding: utf-8 -*-
N =int(input())

loop = 0
biskets = 1
while True :
    if biskets * 2 <= N:
        biskets = biskets * 2
        loop = loop + 1
    else:
        break

m = N - biskets
ans=0

if m ==0:
    ans = loop
else:
    ans = loop +1

print(ans)