import math

def main():
    N = int(input())

    if N == 1:
        print(0)
        return

    if N & 1:
        i = N + 1
        n = 1
    else:
        i = N
        n = 0

    while i > 1:
        i //= 2
        n += 1
        if i & 1 and i > 1:
            i += 1
            n += 1

    print(n)

main()