#include <bits/stdc++.h>
#pragma GCC optimize("O3")
#pragma GCC optimize("unroll-loops")
#pragma GCC target("sse,sse2,sse3,ssse3,sse4,popcnt,abm,mmx,avx,tune=native")
using namespace std;
mt19937 rng(chrono::steady_clock::now().time_since_epoch().count());
int random(int l, int r) { return uniform_int_distribution<int>(l, r)(rng); }
int log2i(int x) { return x ? 31 - __builtin_clz(x) : -1; }
const int N = 1e5 + 2;
struct T {
  long long m, l, r, s;
  T() {}
  T(long long x) {
    s = x;
    m = l = r = max(x, 0LL);
  }
};
T operator+(T a, T b) {
  T ans;
  ans.l = max(a.l, a.s + b.l);
  ans.r = max(b.r, b.s + a.r);
  ans.s = a.s + b.s;
  ans.m = max(a.m, b.m);
  ans.m = max(ans.m, a.r + b.l);
  return ans;
}
T s[N];
int p[N];
int Find(int x) { return x == p[x] ? x : p[x] = Find(p[x]); }
long long ans = 0;
void Union(int x, int y) {
  x = Find(x);
  y = Find(y);
  if (x == y) return;
  if (x > y) swap(x, y);
  s[x] = s[x] + s[y];
  ans = max(ans, s[x].m);
  p[y] = x;
}
vector<int> pos[62];
bool vis[N];
void run() {
  int n, x;
  cin >> n;
  for (int i = 0; i < n; i++)
    cin >> x, s[i] = T(x), p[i] = i, pos[x + 30].push_back(i);
  long long res = 0;
  for (int i = 0; i < 62; i++) {
    for (auto u : pos[i]) {
      vis[u] = true;
      if (u + 1 < n && vis[u + 1]) Union(u, u + 1);
      if (u - 1 >= 0 && vis[u - 1]) Union(u - 1, u);
    }
    if (i >= 30) res = max(res, ans - i + 30);
  }
  cout << res << endl;
}
int main() {
  ios::sync_with_stdio(0);
  cin.tie(NULL);
  cout.tie(NULL);
  int t = 1;
  for (int i = 0; i < t; i++) {
    run();
  }
}
