#include <bits/stdc++.h>
using namespace std;
int n,a[310];
int main()
{
    cin>>n;
    for(int i = 1;i<=n;i++)cin>>a[i];
    sort(a+1,a+1+n);
    int g = 0,sum=0;
    for(int i = 1,j=n;i<=j;i++,j--)
    {
        sum+=(a[j]-g)*(a[j]-g);
        g=a[j];
        sum+=(g-a[i])*(g-a[i]);
        g=a[i];
    }
    cout<<sum;
    return 0;
}

Why I'm wrong???