#include <iostream>
#include <cmath>
using namespace std;

long long arr[262144];
long long normal[18], reversed[18];
long long n;

long long cycler()
{
    bool used[262144];
    long long ans = 0;
    for(int i =0; i<n; i++)
    {
        used[i] = false;
    }
    for(int i =0; i<n ; i++)
    {
        if(!used[i])
        {
            long long path = 1;
            int x= arr[i];
            //cout<<x<<" "<<i<<endl;
            while(x!=i)
            {
                used[x] = true;
                x = arr[x];
                path++;
            }
            ans += (path-1);
        }
    }
    return ans;
}
int main()
{
    cin>>n;
    for(int i =0; i<n; i++)
    {
        cin>>arr[i];
    }
    long long ans = cycler();
    bool xors = false;
    for(int i = log2(n)-1; i>=0; i--)
    {
        long long current_ans = ans;
        //cout<<current_ans<<endl;
        for(int j =0; j<n; j++)
        {
            arr[j] = arr[j] ^(1<<i);
            //cout<<arr[j]<<" "<<(1<<i)<<endl;
        }
        long long new_ans =cycler()+1;
       // cout<<new_ans<<endl;
        if(new_ans > current_ans)
        {
            for(int j =0; j<n; j++)
            {
                arr[j] = arr[j] ^(1<<i);
            }

        }
        else
        {
            ans = new_ans;
        }
    }
    cout<<ans<<endl;

}