#include <bits/stdc++.h>
#define ll long long
#define ull unsigned long long
#define IOS ios::sync_with_stdio(false); cin.tie(0); cout.tie(0);
#define CHECK cout<<"WALKED"<<endl;
#define ls u<<1
#define rs u<<1|1
inline int read(){int x=0,f=1;char ch=getchar();while(ch<'0'||ch>'9'){if(ch=='-')f=-1;ch=getchar();} while(ch>='0' && ch<='9')x=(x<<3)+(x<<1)+ch-'0',ch=getchar();return x*f;}
ll qpow(ll a, ll b, ll mod){ll res = 1;  while (b > 0){if (b & 1) res = res * a % mod;a = a * a % mod;  b >>= 1;  }  return res;}
using namespace std;

const int N = 1e4 + 10;
int n;
int a[N], d[N];
int f[2][600 * N];
int psum[N];

int main()
{
	cin >> n ;
	for (int i = 1; i <= n; i++) 
		cin >> a[i];
	for (int i = 1; i < n; i++) {
		d[i] = a[i + 1] - a[i];
	}
	sort(d + 1, d + n);
	int maxa = a[n], cnt = 1;
	for (int i = 1; i < n; i++) if (!d[i]) cnt++;
	for (int i = 1; i < n; i++) psum[i] = psum[i - 1] + d[i];
	int nw = 0, lst = 1, lm = maxa * n;
	for (int i = 0; i <= lm; i++) f[nw][i] = 1e9;
	f[nw][d[cnt]] = d[cnt] * d[cnt];
	f[nw][d[cnt] * cnt] = d[cnt] * d[cnt] * cnt;
	for (int i = cnt + 1; i < n; i++) {
		nw ^= 1, lst ^= 1;
		for (int s = 0; s <= lm; s++)
			f[nw][s] = 1e9;
		for (int s = 0; s <= lm; s++) {
			if (f[lst][s] == 1e9) continue;
			f[nw][s + d[i] * i] = min(f[nw][s + d[i] * i],
									  f[lst][s] + 2 * s * d[i] + d[i] * d[i] * i);
			f[nw][s + psum[i]] = min(f[nw][s + psum[i]],
									 f[lst][s] + psum[i] * psum[i]);
		}
	}
	
	
	int ans = INT_MAX;
	for (int i = 0; i <= lm; i++)
		if (f[nw][i] != 1e9)
			ans = min(ans, n * f[nw][i] - i * i);
	cout << ans << "\n";
	return 0;
}