#include<cstdio>
#include<iostream>
#include<algorithm>
#include<vector>
#include<string>
#include<set>
#include<map>
#include<deque>
#include<functional>
#include<ctime>
#include<cassert>
#include<cstring>
using namespace std;

#define sz(x) (int)(x.size())
#define fi(a,b) for(int i=a;i<b;++i)
#define fj(a,b) for(int j=a;j<b;++j)
#define fo(a,b) for(int o=a;o<b;++o)
#define fdi(a,b) for(int i=a-1;i>=b;--i)
#define fdj(a,b) for(int j=a-1;j>=b;--j)
#define fdo(a,b) for(int o=a-1;o>=b;--o)
#define pb push_back
#define mp make_pair
typedef long long ll;
typedef pair<int, int> pii;
typedef pair<ll, ll> pll;
typedef double ld;
typedef vector<int> vi;

template<class T> bool uin(T &a, T b){ return (a > b ? a = b, true : false); }
template<class T> bool uax(T &a, T b){ return (a < b ? a = b, true : false); }

/////////////////////////////////
int const M = 2e9;
int const N = 2e5 + 41;
int n;
ll ans;
vi a;
ll suf[N], ds[N];

void solve(){
	fdi(n, 0) suf[i] = a[i] + suf[i+1];
	ds[n-1] = suf[n-1];
	fdi(n-1, 0){
		ds[i] = max(suf[i], ds[i+1]);
	}
	srand(time(0));
	vi p;
	fi(0, n) p.pb(i);
	fi(0, 10)	random_shuffle(p.begin(), p.end());
	int q = 0;
	fi(0, n){
		ll y = 0;
		ll s = 0;
		ld dd = 1.0;
		dd *= ds[p[i]];
		dd *= ds[p[i]];
		dd *= (n - p[i] + 1);
		if(dd < (ld) ans) continue;
		fj(p[i], n){
			y += s * a[j];
			s += a[j];
			uax(ans, y);
		}
		q += n - p[i];
		if(q > M) return;
	}	
}

int main(){
#ifdef LOCAL_DEFINE
	freopen("input.txt","r",stdin);
//	freopen("output.txt","w",stdout);
#endif

	scanf("%d",&n);
	fi(0, n){
		int x;
		scanf("%d",&x);
		a.pb(x);
	}
	solve();		
	printf("%lld\n",ans);
	
#ifdef LOCAL_DEFINE
	fprintf(stderr, "ELAPSED TIME: %.3lf\n", (ld) clock() / CLOCKS_PER_SEC);
#endif	
	
	return 0;
}