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

#define ALL(x) (x).begin(),(x).end()
#define IO ios::sync_with_stdio(false),cin.tie(nullptr);
#define LB(v, x) (ll)(lower_bound(ALL(v),x)-(v).begin())
#define UQ(v) sort(ALL(v)),(v).erase(unique(ALL(v)),v.end())
#define REP(i, n) for(ll i=0; i<(ll)(n); i++)
#define FOR(i, a, b) for(ll i=(ll)(a); (a)<(b) ? i<(b) : i>(b); i+=((a)<(b) ? 1 : -1))
#define chmax(a, b) ((a)<(b) ? ((a)=(b), 1) : 0)
#define chmin(a, b) ((a)>(b) ? ((a)=(b), 1) : 0)

template<typename T> using rpriority_queue=priority_queue<T,vector<T>,greater<T>>;
using ll=long long; const int INF=1e9+10; const ll INFL=4e18; using ld=long double; using ull=uint64_t;
using VI=vector<int>; using VVI=vector<VI>; using VL=vector<ll>; using VVL=vector<VL>;
using PL=pair<ll,ll>; using VP=vector<PL>; using WG=vector<vector<pair<int,ll>>>;


//----------------------------------------------------------

int main() {
    ll N; cin>>N;
    VL A(N); REP(i,N) cin>>A[i];

    ll ans=-INFL;
    REP(t,2) {
        VL pref(N+1),suff(N+1);
        ll sum=0,mn=INFL;
        REP(i,N+1) {
            pref[i]=sum-mn;
            chmin(mn,sum);
            if(i<N) sum+=A[i];
        }
        sum=0,mn=INFL;
        FOR(i,N,-1) {
            suff[i]=sum-mn;
            chmin(mn,sum);
            if(i>0) sum+=A[i-1];
        }

        FOR(i,1,N+1) chmax(pref[i],pref[i-1]);
        FOR(i,N-1,-1) chmax(suff[i],suff[i+1]);

        FOR(i,1,N) chmax(ans,pref[i]*suff[i]);

        REP(i,N) A[i]=-A[i];
    }

    cout<<ans<<endl;
}