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CodeForces - 893B Beautiful Divisors

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題目鏈接 CodeForces - 893B

time limit per test:2 seconds

memory limit per test:256 megabytes input:standard input output:standard output 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.

Examples

Input

3

Output

1

Input

992

Output

496

Tutorial:

Let‘s notice that there are only 8 beautiful numbers less than 105. Generate them all and select the greatest one which is also divisor of n.

Overall complexity: O(1).

#include<iostream>
using namespace std;
int main()
{
    int a[8]={1,6,28,120,496,2016,8128,32640};
    int n;
    cin>>n;
    for (int i=7;i>=0;i--)
    {
        if (n%a[i]==0)
        {
            cout<<a[i]<<endl;
            break;
        }
    }
    return 0;
}

CodeForces - 893B Beautiful Divisors