#include <vector>
#include<iostream>
#include <algorithm>
#include <cmath>
#include <iomanip>
#include <fstream>
#include <string>
#include <set>
#include <deque>
#include <queue>
#include <map>
#include <bitset>
#include <random>
#include <cassert>
#include <unordered_map>
#include <unordered_set>
#include<math.h>
using namespace std;
typedef long long             ll;
typedef unsigned long long     ull;
typedef long double            ld;
#define endl              "\n"
#define all(a)            a.begin(), a.end()
#define allr(a)           a.rbegin(), a.rend()
#define pb                push_back
#define pikachu           push_back
#define F                 first
#define S                  second
#define mp                make_pair
ll inf = 1e18;
void solve() {
    ll n;
    cin >> n;
    vector <ll> a(n + 2, -inf), prefix(n + 1, 0);
    for (ll i = 1; i <= n; i++) {
        cin >> a[i];
        prefix[i] = prefix[i - 1] + a[i];
    }
    vector <ll> stack1(1, 0), stack2(1, n + 1), ans1(n + 2), ans2(n + 2);
    for (ll i = 1; i < n + 2; i++) {
        while (a[stack1.back()] > a[i]) {
            ans1[stack1.back()] = i;
            stack1.pop_back();
        }
        stack1.pikachu(i);
    }
    for (ll i = n + 1; i >= 1; i--) {
        while (a[stack2.back()] > a[i]) {
            ans2[stack2.back()] = i;
            stack2.pop_back();
        }
        stack2.pikachu(i);
    }
    ll pizda = -inf;
    for (ll i = 1; i <= n; i++) {
        ll cnt = 1;
        if (ans2[i] == 0) cnt = 0;
        pizda = max(pizda, a[i] * (prefix[ans1[i]-1] - prefix[ans2[i]]));
    }
    cout << pizda;
}
signed main() {
    ios_base::sync_with_stdio(false);
    cin.tie(nullptr);
    ll t = 1;
    //cin >> t;
    while (t--) {
        solve();
    }
}