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

#include <bits/stdc++.h>
using namespace std;
int n, a[100010], L[100010], R[100010], sl[100010], sr[100010];
int STL[400010], STR[400010];
void buildL(int id, int l, int r) {
  if (l == r) {
    STL[id] = l;
    return;
  }
  int mid = (l + r) >> 1;
  buildL(2 * id, l, mid);
  buildL(2 * id + 1, mid + 1, r);
  if (sl[STL[2 * id]] <= sl[STL[2 * id + 1]])
    STL[id] = STL[2 * id];
  else
    STL[id] = STL[2 * id + 1];
}
void buildR(int id, int l, int r) {
  if (l == r) {
    STR[id] = l;
    return;
  }
  int mid = (l + r) >> 1;
  buildR(2 * id, l, mid);
  buildR(2 * id + 1, mid + 1, r);
  if (sr[STR[2 * id]] < sr[STR[2 * id + 1]])
    STR[id] = STR[2 * id];
  else
    STR[id] = STR[2 * id + 1];
}
int getL(int id, int l, int r, int u, int v) {
  if (l > v || r < u) return -1;
  if (l >= u && r <= v) return STL[id];
  int mid = (l + r) >> 1;
  int x = getL(2 * id, l, mid, u, v), y = getL(2 * id + 1, mid + 1, r, u, v);
  if (x == -1) return y;
  if (y == -1) return x;
  if (sl[x] <= sl[y]) return x;
  return y;
}
int getR(int id, int l, int r, int u, int v) {
  if (l > v || r < u) return -1;
  if (l >= u && r <= v) return STR[id];
  int mid = (l + r) >> 1;
  int x = getR(2 * id, l, mid, u, v), y = getR(2 * id + 1, mid + 1, r, u, v);
  if (x == -1) return y;
  if (y == -1) return x;
  if (sr[x] < sr[y]) return x;
  return y;
}
void solve() {
  cin >> n;
  for (int i = 1; i <= n; i++) cin >> a[i];
  L[1] = 1;
  for (int i = 2; i <= n; i++) {
    if (a[i - 1] > a[i])
      L[i] = i;
    else {
      int j = L[i - 1];
      while (j > 1 && a[j - 1] <= a[i]) j = L[j - 1];
      L[i] = j;
    }
  }
  R[n] = n;
  for (int i = n - 1; i >= 1; i--) {
    if (a[i] < a[i + 1])
      R[i] = i;
    else {
      int j = R[i + 1];
      while (j < n && a[j + 1] <= a[i]) j = R[j + 1];
      R[i] = j;
    }
  }
  sl[0] = 0;
  for (int i = 1; i <= n; i++) sl[i] = sl[i - 1] + a[i];
  sr[n + 1] = 0;
  for (int i = n; i >= 1; i--) sr[i] = sr[i + 1] + a[i];
  buildL(1, 1, n);
  buildR(1, 1, n);
  int ans = -(1e9);
  for (int i = 1; i <= n; i++) {
    int l = L[i], r = R[i], x = 0, y = 0;
    if (l < i) {
      if (l > 1)
        x = sl[i - 1] - sl[getL(1, 1, n, l - 1, i - 1)];
      else
        x = max(sl[i - 1], sl[i - 1] - sl[getL(1, 1, n, l, i - 1)]);
    }
    if (r > i) {
      if (r < n) {
        int ind = getR(1, 1, n, i + 1, r + 1);
        y = sr[i + 1] - sr[ind];
      } else
        y = max(sr[i + 1], sr[i + 1] - sr[getR(1, 1, n, i + 1, r)]);
    }
    ans = max(ans, x + y);
  }
  cout << ans << endl;
}
int main() {
  solve();
  return 0;
}
