Beautiful Divisors

题意翻译

给定n,求n最大的因数s,使s能表示成$(2^k-1)*(2^{k-1})$的形式

题目描述

Recently Luba learned about a special kind of numbers that she calls beautiful numbers. The number is called beautiful iff its binary representation consists of $ k+1 $ consecutive ones, and then $ k $ consecutive zeroes. Some examples of beautiful numbers: - $ 1_{2} $ ( $ 1_{10} $ ); - $ 110_{2} $ ( $ 6_{10} $ ); - $ 1111000_{2} $ ( $ 120_{10} $ ); - $ 111110000_{2} $ ( $ 496_{10} $ ). More formally, the number is beautiful iff there exists some positive integer $ k $ such that the number is equal to $ (2^{k}-1)*(2^{k-1}) $ . Luba has got an integer number $ n $ , and she wants to find its greatest beautiful divisor. Help her to find it!

输入输出格式

输入格式


The only line of input contains one number $ n $ ( $ 1<=n<=10^{5} $ ) — the number Luba has got.

输出格式


Output one number — the greatest beautiful divisor of Luba's number. It is obvious that the answer always exists.

输入输出样例

输入样例 #1

3

输出样例 #1

1

输入样例 #2

992

输出样例 #2

496