#include <bits/stdc++.h>
#include <ext/pb_ds/assoc_container.hpp>
#include <ext/pb_ds/tree_policy.hpp>

using namespace std;
using namespace __gnu_pbds;
using ll = long long;
using ld = long double;

#define all(x)  x.begin(),x.end()
#define v(x) vector<x>
#define nl '\n'
#define fxd(x) fixed << setprecision(x)
template<class t> using ordered_set = tree<t, null_type, less<t>, rb_tree_tag, tree_order_statistics_node_update>;
template<class t> using ordered_multiset = tree<t, null_type, less_equal<t>, rb_tree_tag, tree_order_statistics_node_update>;


int main()
{
    ios_base::sync_with_stdio(false); cin.tie(nullptr); cout.tie(nullptr);
    int n; cin >> n;
    v(ll) arr(n+1);
    for (int i = 1; i <= n; i++)
    {
        cin >> arr[i];
    }
    v(ll) prefsum(n+1,0);
    for (int i = 1; i <= n; i++)
    {
        prefsum[i] = prefsum[i-1] + arr[i];
    }
    v(ll) minprefsum(n+1,0);
    for (int i = 1; i <= n; i++)
    {
        minprefsum[i] = min(prefsum[i],minprefsum[i-1]);
    }
    ll mx = -1e17;
    for (int i = 1; i <= n; i++)
    {
        if(prefsum[i] == minprefsum[i])
        {
            mx = max(mx,arr[i]);
        }
        else
        {
            mx = max(mx,prefsum[i]-minprefsum[i]);
        }
    }
    cout << mx;
    
}