#pragma GCC optimize("Ofast")
#include <unordered_map>
#include <algorithm>
#include <iostream>
#include <cstring>
#include <cstdio>
#include <vector>
#include <bitset>
#include <cmath>
#include <queue>
#include <ctime>
#include <set>
#include <map>
#define int long long
#define rep(i, a, b) for (int i = (a); i <= (b); i ++ )
#define rop(i, a, b) for (int i = (a); i < (b); i ++ )
#define dep(i, a, b) for (int i = (a); i >= (b); i -- )
#define dop(i, a, b) for (int i = (a); i > (b); i -- )

#define Darr(a, L, R) cerr << #a "[" << L << " ~ " << R << "] = "; rep(x, L, R) cerr << a[x] << " "; cerr << '\n';
#define IOS ios::sync_with_stdio(false), cin.tie(0), cout.tie(0)
#define D(x) (cerr << #x << " = " << x << '\n')
#define vit vector<int>::iterator
#define all(x) x.begin(), x.end()
#define min(a, b) (a < b ? a : b)
#define max(a, b) (a > b ? a : b)
#define chkmin(a, b) (a = min(a, b))
#define chkmax(a, b) (a = max(a, b))
#define sit set<int>::iterator
#define lowbit(x) (x & -x)
#define eb emplace_back
#define lb lower_bound
#define ub upper_bound
#define pb push_back
#define pi acos(-1)
#define gc getchar
#define pc putchar
#define db double
#define y second
#define x first

using namespace std;

typedef long long LL;
typedef unsigned long long ULL;
typedef pair<int, int> PII;
typedef pair<db, db> PDD;
const int dx[] = {1, 0, -1, 0};
const int dy[] = {0, 1, 0, -1};
const int mod = 998244353;
const int eps = 1e-9;

const int N = 1000010; int T = 1;
void print(int x) { dep(i, 20, 0) pc(((x >> i) & 1) ? '1' : '0'); }
int qpow(int a, int b = mod - 2, int s = 1) { for (; b; b >>= 1, a = 1ll * a * a % mod) if (b & 1) s = 1ll * s * a % mod; return s; }
namespace IO {
	void read() { return; }
	void write(char ch) { pc(ch); return; }
	void write() { return; }
	template <typename T> void read(T &x) { x = 0; T w = 0; char ch = gc(); while (ch < '0' || ch > '9') w |= (ch == '-'), ch = gc(); while ('0' <= ch && ch <= '9') x = x * 10 + (ch ^ 48), ch = gc(); x = w ? -x : x; }
	template <typename T> void print(T x) { if (!x) return; print<T>(x / 10), pc((x % 10) ^ '0'); }
	template <typename T> void write(T x) { if (x > 0) print<T>(x); else if (x < 0) pc('-'), print<T>(-x); else pc('0'); }
	template <typename T> void write(T x, char en) { write<T>(x), pc(en); }
	template <typename T, typename ...T2> void read(T &s, T2 &...oth) { read(s); read(oth...); return; }
}; using namespace IO;

const int INF = 1e15;
int ans = INF, n, a[N], b[N], c[N];
int calc() {
	int s1 = 0, s2 = 0;
	rep(i, 1, n) a[i] = a[i - 1] + c[i], s1 += a[i], s2 += a[i] * a[i];
	int s = s2 * n - s1 * s1; ans = min(ans, s); return s;
}
void SA() {
	int x = calc();
	for (double t = 1e3; t >= 1e-7; t *= 0.9985) {
		int u = rand() % (n - 1) + 2;
		int v = rand() % (n - 1) + 2; 
		while (v == u) v = rand() % (n - 1) + 2; swap(c[u], c[v]);
		int y = calc(); if (y < x) { x = y; continue; } int d = x - y;
		if ((db)exp(d / t) > (db)rand() / RAND_MAX) { x = y; continue; }
		swap(c[u], c[v]);
	}
}
void sub() {
	srand(time(0)); read(n); 
	rep(i, 1, n) read(a[i]);
	rep(i, 1, n) c[i] = a[i] - a[i - 1];
	while ((db)clock() / CLOCKS_PER_SEC <= 0.97) SA();
	printf("%lld\n", calc());
}
signed main() {
//	freopen("ex_variance4.in", "r", stdin); 
//	read(T);
	while (T -- ) sub();
	return 0;
}