mod = 1000000007
eps = 10**-9


def main():
    import sys
    input = sys.stdin.readline

    D = int(input())
    ok = D
    ng = 0
    mid = (ok+ng)//2
    while ok - ng > 1:
        tmp = 0
        x = mid
        while x:
            tmp += x
            x //= 2
        if tmp >= D:
            ok = mid
        else:
            ng = mid
        mid = (ok+ng)//2
    print(ok)


if __name__ == '__main__':
    main()