// problema tripletteBigs

#include <fstream>
#include <vector>
#include <cmath>
#include <algorithm>
#include <climits>

using namespace std;

const int MAX_N = 10000;
vector<int> nums;
vector<int> arcs, ii, ij;
int m[MAX_N][MAX_N];

int main()
{
    int n,x;

    ifstream fin("input.txt");
    fin>>n;

    for(int i=0; i<n; i++)
        { fin>>x; nums.push_back(x); }

    sort(nums.begin(), nums.end());

    int last=n;
    int finalsum = pow(abs(nums[nums.size()-1]-nums[nums.size()-2]), 2);
    int stepsum = INT_MAX;

    for(int i=2; i<=(int)nums.size()/3; i++) {
        for(int j=1; j<=i; j++) {
int index1 = nums.size()-(2*(i-1))-(j-1)-1;
if(index1>=last) continue;
int index2 = nums.size()-(2*(i-1))-j-1;
int absres = abs(nums[index1]-nums[index2]);
int powres = pow(absres, 2);
            if(powres<stepsum) { stepsum=powres; last=index2; }
            //stepsum = min(powres, stepsum);
} finalsum+=stepsum; stepsum=INT_MAX; }

    ofstream fout("output.txt");
    fout<<finalsum;
    fin.close(); fout.close();

    return 0;
}