10
-3 4 -4 1 1 -4 -5 3 -4 -2
 10
8 9 -10 -10 -4 -3 5 9 -9 9
 6
5 -4 2 -1 2 -2
 11
3 0 1 -2 5 -5 -1 0 3 2 2
 10
4 -2 -2 -2 2 0 1 0 -4 -1
 4
2 2 -3 4
 11
-11 -7 -2 -24 30 -26 24 9 -8 -9 23
 6
30 -29 5 5 -29 30
 24
-8 -6 6 -11 -15 -7 10 -19 -6 21 14 -4 -21 -10 12 17 1 -1 5 19 2 0 -4 -23
 10
-9 -6 -1 9 -2 0 0 -1 5 0
 6
10 -8 3 3 -8 10
 10
-2 -3 -1 4 -3 2 0 1 -5 4
 5
30 -29 10 -1 10
 31
1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 -29 30
 7
30 -20 5 1 3 -20 30
 5
30 -29 4 -3 4
 10
-5 28 -18 -10 9 -2 11 -6 -19 30
 8
4 -10 13 -13 2 2 -11 6
 131
30 -29 29 -28 28 -28 28 -28 28 -28 28 -28 28 -28 28 -28 28 -28 28 -28 28 -28 28 -28 28 -28 28 -28 28 -28 28 -28 28 -28 28 -28 28 -28 28 -28 28 -28 28 -28 28 -28 28 -28 28 -28 28 -28 28 -28 28 -28 28 -28 28 -28 28 -28 28 -28 28 -28 28 -28 28 -28 28 -28 28 -28 28 -28 28 -28 28 -28 28 -28 28 -28 28 -28 28 -28 28 -28 28 -28 28 -28 28 -28 28 -28 28 -28 28 -28 28 -28 28 -28 28 -28 28 -28 28 -28 28 -28 28 -28 28 -28 28 -28 28 -28 28 -28 28 -28 28 -28 27 -26 27
 10
-4 4 0 -2 3 0 1 2 3 -4
 10
-2 -8 5 4 -1 -6 -9 6 1 -6
 7
25 -17 13 13 -25 25 -24
 10
3 -3 2 1 -4 -2 3 -2 -3 0
 10
4 -5 0 4 0 0 -3 1 1 -4
 10
0 4 4 1 -3 4 2 1 4 -1
 17
15 -13 7 8 8 1 -19 12 8 -23 -4 16 -13 -28 10 -30 -14
 4
1 1 -4 10
 11
3 -2 1 1 1 1 1 1 1 -3 4
 7
30 -29 10 10 10 -29 30
 7
25 -13 17 -23 12 12 9
 7
15 -14 10 10 10 -14 15
 10
3 0 0 -4 3 1 -2 -1 -1 4
 6
8 -7 7 -6 5 5
 10
1 -4 -4 4 -2 -3 3 0 -2 3
 15
1 -26 -6 26 7 10 -2 -4 -6 14 -9 25 9 -12 -28
 6
30 -29 10 10 -29 30
 1
6
 2
1 1
 5
0 5 -4 3 -1
 7
5 -4 3 -1 3 -4 4
 10
16 -15 13 -1 10 -2 -20 26 5 -30
 10
-1 2 0 -1 2 -1 4 3 -5 1
 7
5 -4 1 1 1 -4 5
 5
10 -3 -5 3 5
 10
4 -4 3 -2 3 -4 -2 0 1 0
 10
-5 -5 -3 1 -2 2 0 2 -3 4
 10
2 -4 -2 3 1 1 -2 -1 -3 4
 10
-4 -5 4 -3 2 -2 2 1 -1 0
 10
0 -1 4 -2 3 -2 -1 -5 -5 2
 5
19 -6 1 -11 19
 10
1 0 -4 3 -5 3 -1 2 2 -5
 7
5 -5 3 4 3 -5 5
 10
-5 2 -3 -3 -4 3 3 0 2 4
 4
2 3 -10 11
 10
27 -17 15 -22 18 17 -6 2 16 -14
 6
30 -22 6 7 -22 30
 7
30 -25 0 6 9 -2 10
 9
7 2 -1 1 1 -10 6 -1 6
 4
1 -10 1 10
 5
17 -16 12 -11 15
 35
-23 -22 23 4 -22 29 -4 -6 -28 18 -5 21 -7 -8 -11 -7 30 -25 -1 12 19 5 -8 12 -1 10 -24 -19 24 -17 -7 24 20 -22 16
 10
4 -3 1 -2 1 1 0 -4 4 -2
 10
4 -2 1 0 1 -5 -2 1 0 -5
 2
3 9
 9
11 -5 -5 1 2 3 -5 -5 11

1
 8
 1
 4
 1
 2
 15
 5
 36
 2
 3
 1
 9
 28
 4
 1
 7
 2
 1
 7
 4
 13
 1
 1
 13
 16
 1
 6
 20
 21
 20
 1
 5
 1
 44
 10
 0
 1
 0
 2
 9
 5
 2
 3
 1
 2
 2
 1
 1
 3
 3
 6
 8
 2
 29
 6
 13
 5
 1
 1
 30
 1
 1
 3
 3

#define ll long long
#define cn(n)  ll n;cin >> n;
#define mp make_pair
#define pb push_back
#define ff first
#define ss second
#define rep(i, a, b) for (int i = a; i <= b; i++)
#define repd(i, a, b) for (int i = a; i >= b; i--)
#define pii pair<int, int>
#define pll pair<ll, ll>
#define al(v) v.begin(), v.end()
#define oset(X) tree<X, null_type, less<X>, rb_tree_tag, tree_order_statistics_node_update>
#define roset(X) tree<X, null_type, greater<X>, rb_tree_tag, tree_order_statistics_node_update>
const ll MOD = 1000 * 1000 * 1000 + 7;
const ll INF = 1ll * 1000 * 1000 * 1000 * 1000 * 1000 * 1000 + 7;
const ll MOD2 = 998244353;
const long double PI = 3.141592653589793;
#include <bits/stdc++.h>
#include <ext/pb_ds/assoc_container.hpp>
#include <ext/pb_ds/tree_policy.hpp>
#include <functional>
using namespace __gnu_pbds;
using namespace std;
ll power(ll x, ll y, ll p){ll res = 1;x %= p;while (y > 0){if (y & 1)res = (res * x) % p;y = y >> 1;x = (x * x) % p;}return res;}
ll po(ll base, ll powerRaised){if (powerRaised != 0)return (base * po(base, powerRaised - 1));else return 1;}
ll gcd(ll a, ll b){if (b == 0)return a;return gcd(b, a % b);}
ll lcm(ll a, ll b){return (a * b) / gcd(a, b);}
const int N=100009;
pii *tre = new pii[4*N+1]; 
int n;   
vector<ll>pref(N);  
ll res=0;
pii result(pii a,pii b)
{
  if(a.ff>=b.ff)
  return a;
  else return b;
}
pii query(pii *tre,int index,int s,int e,int qs,int qe)
{
	if(qs>e || s>qe)
		return mp(INT_MIN,INT_MIN);
	if(s>=qs && e<=qe)
		return tre[index];
	int m = (s+e)/2;
	pii left_ans = query(tre,2*index,s,m,qs,qe);
	pii right_ans = query(tre,2*index+1,m+1,e,qs,qe);
	return result(left_ans,right_ans);
}
ll findsum(int start,int end)
{
  if(start>end)
  return -1;
  if(start==0)
  return pref[end];
  else return pref[end]-pref[start-1];
}
void solve(int start,int end)
{
  ll sum=findsum(start,end);
  pii pres=query(tre,1,0,n-1,start,end);
  sum-=pres.ff;
  res=max(res,sum);
  if(findsum(start,pres.ss-1)>sum && start<pres.ss-1)
  solve(start,pres.ss-1);
  if(findsum(pres.ss+1,end)>sum && pres.ss+1<end)
  solve(pres.ss+1,end);
}
void buildTree(pii *tre,int *a,int index,int s,int e)
{
	if(s>e)
		return;
	if(s==e)
	{
		tre[index]=mp(a[s],s);
		return ;
	}
	int m = (s+e)/2;
	buildTree(tre,a,2*index,s,m);
	buildTree(tre,a,2*index+1,m+1,e);
	tre[index]= result(tre[2*index],tre[2*index+1]);
	return;
}


int main()
{
  ios_base::sync_with_stdio(false);
  cin.tie(NULL);
  cout.tie(NULL);
#ifndef ONLINE_JUDGE
  freopen("input.txt", "r", stdin);
  freopen("output.txt", "w", stdout);
#endif //*
    cin>>n;
    int a[n+1]={0};
    int b[n+1]={0};
    int start=0;
    int end=0;
    rep(i,0,n-1)
    cin>>a[i];
    buildTree(tre,a,1,0,n-1);	
    // ll ans=0;	
    for(int i=0;i<n;i++)
    {
        if(i>0)
        {
            ll sum=pref[i-1]+a[i];
            if(sum<0)
            {
                pref[i]=0;
                start=end+1;
            }
            else
            {
                pref[i]=sum;
                solve(start,end);
                // cout<<pref[i]<<" ";
                // ans=max(ans,sum-query(tree,1,0,n-1,start,end));
            }
            
        }
        else
        {
            if(a[i]<=0)
            {
                pref[i]=0;
                start=1;
            }
            else pref[i]=a[i];
        }
        end++;
    }
    rep(i,0,n-1)
    b[i]=a[n-1-i];
    buildTree(tre,b,1,0,n-1);
    start=0,end=0;
    pref.assign(n,0);
    for(int i=0;i<n;i++)
    {
        if(i>0)
        {
            ll sum=pref[i-1]+b[i];
            if(sum<0)
            {
                pref[i]=0;
                start=end+1;
            }
            else
            {
                pref[i]=sum;
                solve(start,end);
                // cout<<pref[i]<<" ";
                // ans=max(ans,sum-query(tree,1,0,n-1,start,end));
            }
            
        }
        else
        {
            if(b[i]<=0)
            {
                pref[i]=0;
                start=1;
            }
            else pref[i]=b[i];
        }
        end++;
    }
    cout<<res;

}
