#include <bits/stdc++.h>
#define MOD 1000000007

using namespace std;

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

int main()
{
    ios::sync_with_stdio(false);
    int n;
    cin >> n;
    int ar[n];
    for (int ctr1 = 0; ctr1 < n; ++ctr1)
      cin >> ar[ctr1];
    ll rez = 0;
    ll sum = 0;
    ll c_rez = 0;
    for (int ctr1 = 0; ctr1 < n; ++ctr1) {
      c_rez += ar[ctr1] * sum;
      sum += ar[ctr1];
      rez = max(rez, c_rez);
      if (sum < 0) {
        sum = 0;
        c_rez = 0;
      }
    }
    sum = 0;
    c_rez = 0;
    for (int ctr1 = 0; ctr1 < n; ++ctr1) {
      ar[ctr1] = -ar[ctr1];
      c_rez += ar[ctr1] * sum;
      sum += ar[ctr1];
      rez = max(rez, c_rez);
      if (sum < 0) {
        sum = 0;
        c_rez = 0;
      }
    }
    cout << rez;
    return 0;
}