# coding:UTF-8
import sys

MOD = 10 ** 9 + 7
INF = float('inf')

D = int(input())    # 数字

res = D
for i in range(1, 70):

    # 二分探索
    imin = 0
    imax = D
    while imax - imin > 1:
        imid = imin + (imax - imin) // 2

        check = imid
        t = imid
        for j in range(i):
            t //= 2
            check += t

        # 2分探索する。
        if check <= D:
            imin = imid
        else:
            imax = imid

    check = imin
    t = imin
    for j in range(i):
        t //= 2
        check += t
    if check == D:
        if res > imin:
            res = imin

print("{}".format(res))