#include <bits/stdc++.h>
using ll = long long int;
using namespace std;
struct custom_hash {
  static uint64_t splitmix64(uint64_t x) {
    x += 0x9e3779b97f4a7c15;
    x = (x ^ (x >> 30)) * 0xbf58476d1ce4e5b9;
    x = (x ^ (x >> 27)) * 0x94d049bb133111eb;
    return x ^ (x >> 31);
  }
  size_t operator()(uint64_t x) const {
    static const uint64_t FIXED_RANDOM =
        chrono::steady_clock::now().time_since_epoch().count();
    return splitmix64(x + FIXED_RANDOM);
  }
};
bool printSub(int a[], int sum) {
  if (sum == 0) return true;
  if (sum < 0) return false;
  for (int i = 0; i < 3; ++i) {
    int rem = sum - a[i];
    if (printSub(a, rem)) {
      cout << a[i] << " ";
      return true;
    }
  }
}
void solve() {
  int n, ans = 0;
  cin >> n;
  int a[n];
  for (int i = 0; i < n; ++i) cin >> a[i];
  for (int i = 30; i > 0; --i) {
    int sum = 0;
    for (int j = 0; j < n; ++j) {
      if (a[j] > i) {
        sum = 0;
      } else
        sum = max(a[j], sum + a[j]);
      ans = max(ans, sum - i);
    }
  }
  cout << ans;
}
int main() {
  ios_base::sync_with_stdio(false);
  cin.tie(0);
  cout.tie(0);
  int t = 1;
  while (t--) {
    solve();
  }
  return 0;
}
