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