#include<bits/stdc++.h>

using namespace std;

#define fRead(x)  freopen(x,"r",stdin)
#define fWrite(x) freopen (x,"w",stdout)

#define LL long long
#define ULL unsigned long long
#define ff first
#define ss second
#define pb push_back
#define INF 2e16
#define PI acos(-1.0)
#define mk make_pair
#define pii pair<int,int>
#define pll pair<LL,LL>


#define min3(a,b,c) min(a,min(b,c))
#define max3(a,b,c) max(a,max(b,c))
#define min4(a,b,c,d) min(a,min(b,min(c,d)))
#define max4(a,b,c,d) max(a,max(b,max(c,d)))
#define SQR(a) ((a)*(a))
#define FOR(i,a,b) for(int i=a;i<=b;i++)
#define ROF(i,a,b) for(int i=a;i>=b;i--)
#define REP(i,b) for(int i=0;i<b;i++)
#define MEM(a,x) memset(a,x,sizeof(a))
#define ABS(x) ((x)<0?-(x):(x))

#define scanI(a) scanf("%d",&a)
#define scanI2(a,b) scanI(a) , scanI(b)
#define scanI3(a,b,c) scanI(a), scanI(b), scanI(c)
#define scanI4(a,b,c,d) scanI(a), scanI(b), scanI(c), scanI(d)

#define scanL(a) scanf("%I64d",&a)
#define scanL2(a,b) scanL(a) , scanL(b)
#define scanL3(a,b,c) scanL(a), scanL(b), scanL(c)
#define scanL4(a,b,c,d) scanL(a), scanL(b), scanL(c), scanL(d)

#define SORT(v) sort(v.begin(),v.end())
#define REV(v) reverse(v.begin(),v.end())


#define FastRead ios_base::sync_with_stdio(0);cin.tie(nullptr);
const int N = 500005;

LL ara[N],sum[N],n, mx = 0;
vector<int>ran;
int vis[N];
int max_sub()
{
   LL s = 0 , index = 0 , maxi = 0;
   for(int i = n;i>=1;i--){
      s = s + (- ara[i]);
      if(s < maxi){
         maxi = s;
         index = i;
      }
   }
   return index;
}
int main()
{
   srand(time(NULL));
   int timer = 0;
   cin >> n;
   FOR(i,1,n)cin >> ara[i];
   FOR(i,1,n)ran.push_back(i);
   random_shuffle(ran.begin(),ran.end());
   for(int i = 1;i<=10;i++)ran.push_back(i);
   for(int i = 1;i<=10;i++)ran.push_back(n - i + 1);
   for(int i = 1;i<=10;i++)ran.push_back(n/2 + i);
   for(int i = 1;i<=10;i++)ran.push_back(n/3 + i);
   for(int i = 1;i<=10;i++)ran.push_back(n/4 + i);
   for(int i = 1;i<=10;i++)ran.push_back(n/5 + i);

   for(int i = 1;i<=10;i++)ran.push_back(n - n/2 + i);
   for(int i = 1;i<=10;i++)ran.push_back(n - n/3 + i);
   for(int i = 1;i<=10;i++)ran.push_back(n - n/4 + i);
   for(int i = 1;i<=10;i++)ran.push_back(n - n/5 + i);
   ran.push_back(max_sub());
   REV(ran);
   for(int i = 0;i < ran.size();i++){
      LL in = ran[i];
      if(in < 1 or in > n)continue;
      if(vis[in])continue;
      vis[in] = 1;
      LL s = 0 , ans = 0;
      for(int j = in ;j <= n;j++){
         ans = ans + s * ara[j];
         mx = max(mx,ans);
         s = s + ara[j];
         timer++;
      }
      if(timer > 9e8)break;
   }
   cout << mx << "\n";



}