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

import java.io.*;
import java.util.*;
import java.math.*;
import java.awt.Point;
 
public class Main {
	//static final long MOD = 998244353L;
	//static final long INF = 1000000000000000007L;
	static String letters = "abcdefghijklmnopqrstuvwxyz";
	static final long MOD = 1000000007L;
	static final int INF = 1000000007;
	
	public static void main(String[] args) {
		FastScanner sc = new FastScanner();
		PrintWriter pw = new PrintWriter(System.out);
		
		int N = sc.ni();
		int[] nums = new int[N+2];
		SegmentTree numST = new SegmentTree(N+2);
		for (int i = 1; i <= N; i++) {
			nums[i] = sc.ni();
			numST.update(0, 0, N+1, i, nums[i]);
		}
		SegmentTree rightST = new SegmentTree(N+2);
		int[] rightPref = new int[N+2];
		for (int i = 1; i <= N; i++) {
			rightPref[i] = rightPref[i-1]+nums[i];
			rightST.update(0, 0, N+1, i, rightPref[i]);
		}
		int[] leftPref = new int[N+2];
		SegmentTree leftST = new SegmentTree(N+2);
		for (int i = N; i >= 1; i--) {
			leftPref[i] = leftPref[i+1]+nums[i];
			leftST.update(0, 0, N+1, i, leftPref[i]);
		}
		
		int ans = 0;
		for (int i = 1; i <= N; i++) {
			if (nums[i] <= 0) continue;
			//binary search to find the leftmost point that is <= nums[i]
			int low = 1;
			int high = i;
			while (low < high) {
				int med = (low+high)/2;
				if (numST.query(0, 0, N+1, med, i) == nums[i]) {
					high = med;
				} else {
					low = med+1;
				}
			}
			
			int L = low;
			
			//binary search to find the rightmost point that is <= nums[i]
			low = i;
			high = N;
			while (low < high) {
				int med = (low+high+1)/2;
				if (numST.query(0, 0, N+1, i, med) == nums[i]) {
					low = med;
				} else {
					high = med-1;
				}
			}
			
			int R = low;
			
			int add1 = leftST.query(0, 0, N+1, L, i)-leftPref[i];
			int add2 = rightST.query(0, 0, N+1, i, R)-rightPref[i];
			ans = Math.max(ans,add1+add2);
		}
		pw.println(ans);
		
		pw.close();
	}
	
	static class SegmentTree {
		public int[] tree;
		public int N;

		//Zero initialization
		public SegmentTree(int n) {
			N = n;
			tree = new int[4*N+1];
		}
		
		public int query(int treeIndex, int lo, int hi, int i, int j) {
			// query for arr[i..j]
			if (lo > j || hi < i)
				return 0;
			if (i <= lo && j >= hi)
				return tree[treeIndex];
			int mid = lo + (hi - lo) / 2;

			if (i > mid)
				return query(2 * treeIndex + 2, mid + 1, hi, i, j);
			else if (j <= mid)
				return query(2 * treeIndex + 1, lo, mid, i, j);

			int leftQuery = query(2 * treeIndex + 1, lo, mid, i, mid);
			int rightQuery = query(2 * treeIndex + 2, mid + 1, hi, mid + 1, j);

			// merge query results
			return merge(leftQuery, rightQuery);
		}

		public void update(int treeIndex, int lo, int hi, int arrIndex, int val) {
			if (lo == hi) {
				tree[treeIndex] = val;
				return;
			}

			int mid = lo + (hi - lo) / 2;

			if (arrIndex > mid)
				update(2 * treeIndex + 2, mid + 1, hi, arrIndex, val);
			else if (arrIndex <= mid)
				update(2 * treeIndex + 1, lo, mid, arrIndex, val);

			// merge updates
			tree[treeIndex] = merge(tree[2 * treeIndex + 1], tree[2 * treeIndex + 2]);
		}

		public int merge(int a, int b) {
			return Math.max(a,b);
		}
	}
	
 
	public static long dist(long[] p1, long[] p2) {
		return (Math.abs(p2[0]-p1[0])+Math.abs(p2[1]-p1[1]));
	}
	
	//Find the GCD of two numbers
	public static long gcd(long a, long b) {
		if (a < b) return gcd(b,a);
		if (b == 0)
			return a;
		else
			return gcd(b,a%b);
	}
	
	//Fast exponentiation (x^y mod m)
	public static long power(long x, long y, long m) { 
		if (y < 0) return 0L;
		long ans = 1;
		x %= m;
		while (y > 0) { 
			if(y % 2 == 1) 
				ans = (ans * x) % m; 
			y /= 2;  
			x = (x * x) % m;
		} 
		return ans; 
	}
	
	public static int[] shuffle(int[] array) {
		Random rgen = new Random();
		for (int i = 0; i < array.length; i++) {
		    int randomPosition = rgen.nextInt(array.length);
		    int temp = array[i];
		    array[i] = array[randomPosition];
		    array[randomPosition] = temp;
		}
		return array;
	}
	
	public static long[] shuffle(long[] array) {
		Random rgen = new Random();
		for (int i = 0; i < array.length; i++) {
		    int randomPosition = rgen.nextInt(array.length);
		    long temp = array[i];
		    array[i] = array[randomPosition];
		    array[randomPosition] = temp;
		}
		return array;
	}
	
	public static int[][] shuffle(int[][] array) {
		Random rgen = new Random();
		for (int i = 0; i < array.length; i++) {
		    int randomPosition = rgen.nextInt(array.length);
		    int[] temp = array[i];
		    array[i] = array[randomPosition];
		    array[randomPosition] = temp;
		}
		return array;
	}
	
    public static int[][] sort(int[][] array) {
    	//Sort an array (immune to quicksort TLE)
 
		Arrays.sort(array, new Comparator<int[]>() {
			  @Override
        	  public int compare(int[] a, int[] b) {
				  return a[0]-b[0]; //ascending order
	          }
		});
		return array;
	}
    
    public static long[][] sort(long[][] array) {
    	//Sort an array (immune to quicksort TLE)
		Random rgen = new Random();
		for (int i = 0; i < array.length; i++) {
		    int randomPosition = rgen.nextInt(array.length);
		    long[] temp = array[i];
		    array[i] = array[randomPosition];
		    array[randomPosition] = temp;
		}
		Arrays.sort(array, new Comparator<long[]>() {
			  @Override
        	  public int compare(long[] a, long[] b) {
				  if (a[0] < b[0])
					  return -1;
				  else
					  return 1;
	          }
		});
		return array;
	}
    
    static class FastScanner { 
        BufferedReader br; 
        StringTokenizer st; 
  
        public FastScanner() { 
            br = new BufferedReader(new InputStreamReader(System.in)); 
        } 
  
        String next() { 
            while (st == null || !st.hasMoreElements()) { 
                try { 
                    st = new StringTokenizer(br.readLine());
                } catch (IOException  e) { 
                    e.printStackTrace(); 
                } 
            } 
            return st.nextToken(); 
        }
        
        int ni() { 
            return Integer.parseInt(next()); 
        }
  
        long nl() { 
            return Long.parseLong(next()); 
        } 
  
        double nd() { 
            return Double.parseDouble(next()); 
        } 
  
        String nextLine() {
            String str = ""; 
            try { 
                str = br.readLine(); 
            } catch (IOException e) {
                e.printStackTrace(); 
            } 
            return str;
        }
    }
}