#include <bits/stdc++.h>

using namespace std;

typedef long long ll;
typedef pair < int, int > ii;

const int N = 5e5 + 5;

int n;
int a[N];
ll pre[N], presq[N];

const ll is_query = -(1LL<<62);
struct Line {
    ll m, b;
    mutable function<const Line*()> succ;
    bool operator<(const Line& rhs) const {
        if (rhs.b != is_query) return m < rhs.m;
        const Line* s = succ();
        if (!s) return 0;
        ll x = rhs.m;
        return b - s->b < (s->m - m) * x;
    }
};
struct HullDynamic : public multiset<Line> { // will maintain upper hull for maximum
    bool bad(iterator y) {
        auto z = next(y);
        if (y == begin()) {
            if (z == end()) return 0;
            return y->m == z->m && y->b <= z->b;
        }
        auto x = prev(y);
        if (z == end()) return y->m == x->m && y->b <= x->b;
        return (x->b - y->b)*(z->m - y->m) >= (y->b - z->b)*(y->m - x->m);
    }
    void insert_line(ll m, ll b) {
        auto y = insert({ m, b });
        y->succ = [=] { return next(y) == end() ? 0 : &*next(y); };
        if (bad(y)) { erase(y); return; }
        while (next(y) != end() && bad(next(y))) erase(next(y));
        while (y != begin() && bad(prev(y))) erase(prev(y));
    }
    ll eval(ll x) {
        auto l = *lower_bound((Line) { x, is_query });
        return l.m * x + l.b;
    }
}trick;

int main() {

	scanf("%d", &n);

	for(int i = 1; i <= n; i++) {
		scanf("%d", a + i);
		pre[i] = pre[i - 1] + a[i];
		presq[i] = presq[i - 1] + (ll) a[i] * a[i];
	}

	ll ans = 0;

	for(int r = 1; r <= n; r++) {
		ll c = pre[r] * pre[r] - presq[r];
		trick.insert_line(-2*pre[r-1],presq[r-1]+pre[r-1]*pre[r-1]);
		ans = max(ans, trick.eval(pre[r])+c);
		// for(int l = 1; l <= r; l++) {
		// 	ans = max(ans, pre[l - 1] * pre[l - 1] - 2 * pre[r] * pre[l - 1] + presq[l - 1]);
		// }
	}

	printf("%lld\n", ans/2);

    return 0;

}