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

int main(){
    constexpr int inf = 1 << 30;
    ios::sync_with_stdio(false);
    cin.tie(0);
    int n;
    cin >> n;
    vector<int> a(n);
    for(auto &&v : a) cin >> v;
    if(n == 2){
        cout << (ll)(a[0]) * a[1] << '\n';
        return 0;
    }
    vector<int> Lmx(n + 1, -inf), Lmn(n + 1, inf);
    int sv = 0, mn = 0, mx = 0;
    for(int i = 0; i < n; i++){
        sv += a[i];
        Lmx[i + 1] = max(Lmx[i], sv - mn);
        Lmn[i + 1] = min(Lmn[i], sv - mx);
        mn = min(mn, sv);
        mx = max(mx, sv);
    }
    sv = mn = mx = 0;
    ll ans = -(1ll << 60);
    int mx2 = -inf, mn2 = inf;
    for(int i = n - 1; i >= 1; i--){
        sv += a[i];
        mx2 = max(mx2, sv - mn);
        mn2 = min(mn2, sv - mx);
        ans = max(ans, Lmx[i] * (ll)(mx2));
        ans = max(ans, Lmn[i] * (ll)(mn2));
        mn = min(mn, sv);
        mx = max(mx, sv);
    }
    cout << ans << '\n';
}