Educational Codeforces Round 33 (Rated for Div. 2) B题

B. Beautiful Divisors

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:

12 (110);
1102 (610);
11110002 (12010);
1111100002 (49610).
More formally, the number is beautiful iff there exists some positive integer k such that the number is equal to (2k - 1) * (2k - 1).

Luba has got an integer number n, and she wants to find its greatest beautiful divisor. Help her to find it!

Input
The only line of input contains one number n (1 ≤ n ≤ 105) — the number Luba has got.

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

Input

Output

思路：看了看数据范围。QAQ，发现可以打表===水过

AC代码：

 #include<bits/stdc++.h>

 using namespace std;
 int arr[]={,,, , ,, ,,  ,};
 int main(){
     int n;
     cin>>n;
     for(int i=;i>=;i--){
         if(arr[i]>n)
             continue;
         if(arr[i]==n){
             printf("%d",n);return ;
         }
         if(n%arr[i]==){
             cout<<arr[i];return ;
         }
     }
     return ;
 }