#include <cstdlib>
#include <fstream>
// #include <cassert>
//#include <iostream>

using namespace std;

int N;

const int MAX_N = 10000;

const int MAX_VAL = 100000;
const int offset = 50000;

int rawNum[MAX_VAL];

int num[MAX_N];
int delta[MAX_N-1][3];

int freeNum;

int MIN_FREENUM;

int minK;

int notepad[MAX_N][MAX_N];

void minCost(int i, int k);
	
int main() {

  /*for(int i = 0; i < MAX_N; i++)
    for(int j = 0; j < MAX_N; j++)
      notepad[i][j] = -1;*/

  for(int i = 0; i < MAX_VAL; i++)
		rawNum[i] = 0;

	for(int i = 0; i < MAX_N-1; i++)
		delta[i][0] = 0;

	ifstream fin("input.txt");

	fin >> N;
	
	freeNum = N;

  MIN_FREENUM = N / 3;
		
	int v;
	
	for(int i = 0; i < N; i++) {
		fin >> v;
		rawNum[v+offset]++;
	}
	
	fin.close();

  // ordino l'input
  int x = 0;
	for(int i = 0; i < N; i++) {
		
    while(rawNum[x] == 0 && x < MAX_VAL)
      x++;
      
    num[i] = x-offset;
    
    rawNum[x]--;
    
    if(i > 0) {
      delta[i-1][1] = num[i];
      delta[i-1][2] = num[i-1];
      delta[i-1][0] = delta[i-1][1] - delta[i-1][2];
    }
		
	}
	
	for(int i = 0; i < N; i++)
	  rawNum[num[i]+offset]++;
	
	minK = 999999;
	  
	int nStart = N-2;
	
	// update
  rawNum[delta[nStart][1] + offset]--;
  rawNum[delta[nStart][2] + offset]--;
  freeNum -= 2;
	  
	minCost(nStart, delta[nStart][0] * delta[nStart][0]); 
  
  //cout << minK << "\n";
  
  ofstream fout("output.txt");
  
  fout << minK << "\n";
  
  fout.close();

	return 0;

}


void minCost(int i, int k) {
  
  /*if(notepad[i][k] != -1) {
     if(notepad[i][k] < minK)
       minK = notepad[i][k];
     return;
  }*/

  if(freeNum <= MIN_FREENUM) {
    
    if(k < minK) {
    
      bool check = true;
      
      for(int x = MIN_FREENUM; x < N-1; x++) {
        int a1 = rawNum[num[x]+offset];
        int a2 = rawNum[num[x+1]+offset];
        if( (num[x] == num[x+1] && a1 == 2) || (num[x] != num[x+1] && a1 >= 1 && a2 >= 1) ) {
          check = false;
          break;
        }
      }
      
      if(check)
        notepad[i][k] = minK = k;
      
    }
    
    return;
  }
  
  if(i < 1)
    return;

  int m1;

  int c = delta[i][1]+offset;
  int b = delta[i][2]+offset;
  
  if( (b != c && rawNum[b] > 0 && rawNum[c] > 0) || (b == c && rawNum[b] >= 2) ) {
  
    int ki = delta[i][0] * delta[i][0];
    
    // update
    rawNum[b]--;
    rawNum[c]--;
    freeNum -= 2;
      
    minCost(i - 1, k + ki);
    
    // update
    rawNum[b]++;
    rawNum[c]++;
    freeNum += 2;
      
  }
  
  minCost(i - 1, k);  

}