#include <bits/stdc++.h>
using namespace std;

const int N = 510000;

struct PT {
	long long x, y;
	bool operator<(const PT &rhs) const {
		return x < rhs.x || (x == rhs.x && y < rhs.y);
	}
} L[N], R[N];

long long cross(PT p, PT p1, PT p2) {
	return (p1.x - p.x) * (p2.y - p.y) - (p2.x - p.x) * (p1.y - p.y);
}

const long long inf = 1LL<<61;

vector<PT> V[1<<20];
long long s[N], t[N];

long long solve(int u, int l, int r) {
//	cerr << u << ' ' << l << ' ' << r << endl;
	if (l == r) {
		V[u].push_back((PT){-2LL*s[l], t[l]+1LL*s[l]*s[l]});
		return -inf;
	}
	int m = l + r >> 1;
	long long ret = -inf;
	ret = max(ret, solve(u + u, l, m));
	ret = max(ret, solve(u + u + 1, m + 1, r));
//	cerr << u << " " << "k" << endl;
	assert(V[u+u].size() == m-l+1);
	assert(V[u+u+1].size() == r-m);
	for (int i = 0, j = 0; i < V[u+u].size() || j < V[u+u+1].size(); ) {
		if (i == V[u+u].size() || (j < V[u+u+1].size() && V[u+u+1][j] < V[u+u][i])) {
			V[u].push_back(V[u+u+1][j]), j++;
		} else {
			V[u].push_back(V[u+u][i++]);
		}
	}
//	cerr << u << ' ' << V[u].size() << endl;
	assert(V[u].size() == r-l+1);
	int n = 0;
	for (int i = 0; i < V[u+u].size(); i++) {
		PT cur = V[u+u][i];
		while (n > 1 && cross(L[n-2], L[n-1], cur) >= 0) n--;
		L[n++] = cur;
	}
	int h = 0;
//	cerr << "ok" << endl;
	for (int i = (int)V[u+u+1].size()-1; i >= 0; i--) {
		long long x = -V[u+u+1][i].x / 2;
		long long y = -V[u+u+1][i].y + 2*x*x;
//		cerr << x << ' ' << y << endl;
		while (h < n-1 && L[h].x * x + L[h].y < L[h+1].x * x + L[h+1].y) h++;
		ret = max(ret, L[h].x * x + L[h].y + y);
	}
	return ret;
}

int main() {
	int n; scanf("%d", &n);
	for (int i = 1; i <= n; i++) {
		int x; scanf("%d", &x);
		s[i] = s[i-1] + x;
		t[i] = t[i-1] + 1LL * x * x;
	}
	printf("%lld\n", solve(1, 0, n) / 2);
	return 0;
}