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

int main(){
    ios_base::sync_with_stdio(false);
    cin.tie(nullptr);

    int N; cin >> N;
    vector<long long> Akane(N);
    for(auto &a : Akane) cin >> a;
    if(N == 2){cout << Akane.at(0)*Akane.at(1) << endl; return 0;}

    vector<long long> Aoi(N+1);
    for(int i=1; i<=N; i++) Aoi.at(i) = Aoi.at(i-1)+Akane.at(i-1);

    long long answer = 0,plus = 0,minus = 0;
    for(auto a : Akane){
        if(a == 0){answer = 0; continue;}
        if(a > 0) plus++;
        else minus++;
    }
    if(plus > 1){
        vector<long long> L(N+1),R(N+1);
        long long mina = 0;
        for(int i=1; i<N; i++){
            mina = min(mina,Aoi.at(i));
            L.at(i) = Aoi.at(i)-mina;
        }
        long long maxa = Aoi.at(N);
        for(int i=N-1; i>0; i--){
            maxa = max(maxa,Aoi.at(i));
            R.at(i) = maxa-Aoi.at(i);
        }
        maxa = 0;
        for(int i=1; i<N; i++) maxa = max(maxa,L.at(i)),answer = max(answer,maxa*R.at(i));
    }
    if(minus > 1){
        vector<long long> L(N+1),R(N+1);
        long long maxa = 0;
        for(int i=1; i<N; i++){
            maxa = max(maxa,Aoi.at(i));
            L.at(i) = maxa-Aoi.at(i);
        }
        long long mina = Aoi.at(N);
        for(int i=N-1; i>0; i--){
            mina = min(mina,Aoi.at(i));
            R.at(i) = Aoi.at(i)-mina;
        }
        maxa = 0;
        for(int i=1; i<N; i++) maxa = max(maxa,L.at(i)),answer = max(answer,maxa*R.at(i));
    }
    cout << answer << endl;
}