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

/**
 * @author egaeus
 * @mail sebegaeusprogram@gmail.com
 * @veredict Not sended
 * @url <https://codeforces.com/problemset/problem/>
 * @category ?
 * @date 28/05/2020
 **/

import java.io.*;
import java.util.*;

import static java.lang.Integer.*;
import static java.lang.Math.*;

public class CFD {
    public static void main(String args[]) throws Throwable {
        BufferedReader in = new BufferedReader(new InputStreamReader(System.in));
        for (String ln; (ln = in.readLine()) != null && !ln.equals(""); ) {
            int N = parseInt(ln);
            int[] arr = new int[N];
            StringTokenizer st = new StringTokenizer(in.readLine());
            for (int i = 0; i < arr.length; i++)
                arr[i] = parseInt(st.nextToken());
            int[] maxs = new int[N];
            int[] mins = new int[N];
            Arrays.fill(mins, -1);
            Arrays.fill(maxs, N);
            int[] values = new int[61];
            Arrays.fill(values, -1);
            values[arr[0] + 30] = 0;
            for (int i = 1; i < N; i++) {
                for (int j = arr[i] + 1; j <= 30; j++)
                    mins[i] = Math.max(mins[i], values[j + 30]);
                values[arr[i] + 30] = i;
            }
            Arrays.fill(values, N);
            values[arr[N - 1] + 30] = N - 1;
            for (int i = N - 2; i >= 0; i--) {
                for (int j = arr[i] + 1; j <= 30; j++)
                    maxs[i] = Math.min(maxs[i], values[j + 30]);
                values[arr[i] + 30] = i;
            }
            int[] arr1 = new int[N];
            arr1[N - 1] = arr[N - 1];
            for (int i = 1; i < N; i++)
                arr1[N - i - 1] = arr[N - i - 1] + arr1[N - i];
            for (int i = 1; i < N; i++)
                arr[i] += arr[i - 1];
            int s = MIN_VALUE;
            RMQ rmq = new RMQ(arr);
            RMQ rmq1 = new RMQ(arr1);
            for (int i = 0; i < N; i++) {
                int a = rmq.get(i, maxs[i]) - arr[i];
                int b = rmq1.get(mins[i] + 1, i+1) - arr1[i];
                s = Math.max(s, a+b);
            }
            System.out.println(s);
        }
    }

    static class RMQ {
        int N;
        int D;
        int[] arr;
        int[][] cotas;
        int[] vals;
        int max;

        public RMQ(int[] arr) {
            N = arr.length;
            D = (int) Math.ceil(Math.sqrt(N));
            this.arr = arr;
            cotas = new int[(int) Math.ceil(1. * N / D)][];
            vals = new int[(int) Math.ceil(1. * N / D)];
            //Change init
            Arrays.fill(vals, MIN_VALUE);
            for (int i = 0, j = 0; j < cotas.length; i += D, j++)
                cotas[j] = new int[]{i, Math.min(i + D, arr.length)};
            for (int i = 0; i < cotas.length; i++) {
                for (int j = cotas[i][0]; j < cotas[i][1]; j++) {
                    //Change function
                    vals[i] = Math.max(vals[i], arr[j]);
                }
            }


        }

        int get(int a, int b) {
            int desde = -1, hasta = -1;
            for (int i = 0; i < cotas.length; i++) {
                if (a >= cotas[i][0] && a < cotas[i][1]) {
                    desde = i;
                }
                if (b > cotas[i][0] && b <= cotas[i][1]) {
                    hasta = i;
                }
            }
            //Change init
            int min = MIN_VALUE;
            for (int i = desde + 1; i < hasta; i++)
                //Change function
                min = Math.max(min, vals[i]);
            int izq = getSegementIzq(desde, a, b);
            int der = (desde != hasta ? getSegementDer(hasta, a, b - 1) : MIN_VALUE);
            //Change function
            return Math.max(min, Math.max(izq, der));
        }

        int getSegementIzq(int i, int a, int b) {
            //Change init
            int min = MIN_VALUE;
            for (int j = a; j < Math.min(cotas[i][1], b); j++)
                //Change function
                min = Math.max(min, arr[j]);
            return min;
        }

        int getSegementDer(int i, int a, int b) {
            //Change init
            int min = MIN_VALUE;
            for (int j = b; j >= Math.max(a, cotas[i][0]); j--)
                //Change function
                min = Math.max(min, arr[j]);
            return min;
        }
    }
}
