#include <bits/stdc++.h>
using namespace std;
int pct(int x) { return __builtin_popcount(x); }
int pct(long long x) { return __builtin_popcountll(x); }
int bt(int x) { return 31 - __builtin_clz(x); }
int bt(long long x) { return 63 - __builtin_clzll(x); }
int cdiv(int a, int b) { return a / b + !(a < 0 || a % b == 0); }
long long cdiv(long long a, long long b) {
  return a / b + !(a < 0 || a % b == 0);
}
int nxt_C(int x) {
  int c = x & -x, r = x + c;
  return (((r ^ x) >> 2) / c) | r;
}
long long nxt_C(long long x) {
  long long c = x & -x, r = x + c;
  return (((r ^ x) >> 2) / c) | r;
}
vector<int> get_bits(int mask) {
  vector<int> bb;
  while (mask) {
    int b = bt(mask);
    bb.push_back(b);
    mask ^= (1 << b);
  }
  reverse(bb.begin(), bb.end());
  return bb;
}
int get_mask(vector<int> v) {
  int mask = 0;
  for (int x : v) {
    mask ^= (1 << x);
  }
  return mask;
}
template <typename T>
void uniq(vector<T> &v) {
  sort(v.begin(), v.end());
  v.resize(unique(v.begin(), v.end()) - v.begin());
}
mt19937_64 rng(chrono::steady_clock::now().time_since_epoch().count());
long long rand(long long l, long long r) {
  uniform_int_distribution<long long> uid(l, r);
  return uid(rng);
}
void sc() {}
template <typename Head, typename... Tail>
void sc(Head &H, Tail &...T) {
  cin >> H;
  sc(T...);
}
const int mod = 1e9 + 7;
int pwr(int a, long long b) {
  int ans = 1;
  while (b) {
    if (b & 1) ans = (ans * 1LL * a) % mod;
    a = (a * 1LL * a) % mod;
    b >>= 1;
  }
  return ans;
}
template <class T, size_t MAXN>
struct FastSegmentTree {
  int n;
  T st[MAXN << 1];
  void build(int n) {
    this->n = n;
    for (int i = n - 1; i > 0; i--) {
      st[i] = max(st[i << 1], st[i << 1 | 1]);
    }
  }
  T query(int l, int r) {
    l += n, r += n + 1;
    T res = -1e9;
    for (; l < r; l >>= 1, r >>= 1) {
      if (l & 1) res = max(res, st[l++]);
      if (r & 1) res = max(res, st[--r]);
    }
    return res;
  }
};
const int N = 1e5 + 5;
int a[N];
int pre[N];
void solve() {
  int n;
  sc(n);
  vector<pair<int, int> > v;
  for (int i = 1; i <= n; i++) {
    sc(a[i]);
    pre[i] = pre[i - 1] + a[i];
    v.push_back({a[i], i});
  }
  sort(v.begin(), v.end());
  reverse(v.begin(), v.end());
  FastSegmentTree<int, N> seg, seg1;
  for (int i = 0; i <= n; i++) {
    seg.st[n + 1 + i] = pre[i];
    seg1.st[n + 1 + i] = -pre[i];
  }
  seg.build(n + 1);
  seg1.build(n + 1);
  int ans = -INT_MAX;
  set<int> s;
  s.insert(n + 1);
  s.insert(0);
  for (auto x : v) {
    auto it = s.upper_bound(x.second);
    int r = (*it) - 1;
    it--;
    int l = (*it) + 1;
    int i = x.second;
    ans = max(ans, seg1.query(l - 1, i - 1) + seg.query(i, r) - x.first);
    s.insert(i);
  }
  cout << ans << '\n';
}
int main() {
  ios ::sync_with_stdio(0);
  cin.tie(0);
  cout.tie(0);
  int t = 1;
  for (int tt = 1; tt <= t; tt++) {
    solve();
  }
  return 0;
}
