CodeForces - 893B Beautiful Divisors

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 (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!

Input

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

#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;
}