import math
i = int(input())
j = int(math.log(i, 2))
if i == 2**j:
    print(j)
elif i > 2**j and i %2 == 0 or i == 2**j +1:
    print(j+1)
elif i > 2**j and i %2 != 0 and i != 2**j +1:
    print(j +2)