import sys
read = sys.stdin.buffer.read
readline = sys.stdin.buffer.readline
readlines = sys.stdin.buffer.readlines
sys.setrecursionlimit(10 ** 7)

n = int(readline())
x = 1
if x == n:
    print(0)
    exit()
for i in range(n):
    if x * 2 < n:
        x *= 2
    else:
        print(i + 1 + x * 2 - n)
        break