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

# -*- coding:utf-8 -*-

"""

created by shuangquan.huang at 2020/6/4

"""

import collections
import time
import os
import sys
import bisect
import heapq
from typing import List

INF = 10**7

class SegmentTree:
    def __init__(self, size, useMax):
        n = size * 4 + 1
        v = -INF if useMax else INF
        self.data = [v for _ in range(n)]
        self.size = size
        self.n = n
        self.useMax = useMax
        self.lazy = [False for _ in range(n)]
    
    def push(self, index):
        pass
    
    def build(self):
        pass
    
    def update(self, index, val):
        self.update_impl(1, 0, self.size-1, index, index, val)
    
    def query(self, start, end):
        return self.query_impl(1, 0, self.size-1, start, end)
    
    def update_impl(self, index, nodel, noder, targetl, targetr, val):
        if nodel > noder or targetl > targetr:
            return -INF if self.useMax else INF
        
        self.push(index)
        if nodel == targetl and noder == targetr:
            self.data[index] = max(self.data[index], val) if self.useMax else min(self.data[index], val)
            return self.data[index]
        
        m = (nodel + noder) // 2
        a =  self.update_impl(index * 2, nodel, min(m, noder), targetl, min(m, targetr), val)
        b =  self.update_impl(index * 2 + 1, max(nodel, m+1), noder, max(targetl, m+1), targetr, val)
        c = max(a, b) if self.useMax else min(a, b)
        self.data[index] = max(self.data[index], c) if self.useMax else min(self.data[index], c)
        
        return c
        
    def query_impl(self, index, nodel, noder, targetl, targetr):
        if nodel > noder or targetl > targetr:
            return -INF if self.useMax else INF
    
        self.push(index)
        if nodel == targetl and noder == targetr:
            return self.data[index]
        
        m = (nodel + noder) // 2
        a = self.query_impl(index * 2, nodel, min(m, noder), targetl, min(m, targetr))
        b = self.query_impl(index * 2 + 1, max(m+1, nodel), noder, max(m+1, targetl), targetr)
        c = max(a, b) if self.useMax else min(a, b)
        
        return c
    
    
def solve(N, A):
    presum = [0]
    for v in A:
        presum.append(presum[-1] + v)
    
    left = []
    q = []
    # print(presum)
    st = SegmentTree(N, useMax=False)
    for i, v in enumerate(A):
        while q and q[-1][0] <= v:
            q.pop()
        j = q[-1][1] + 1 if q else 0
        left.append(max(presum[i] - st.query(j, i-1), 0))
        st.update(i, presum[i])
        q.append((v, i))
        # print(st.data)
        # print([st.query(i, i) for i in range(N+1)])
        
    right = []
    q = []
    st = SegmentTree(N, useMax=True)
    for i in range(N-1, -1, -1):
        v = A[i]
        while q and q[-1][0] <= v:
            q.pop()
        j = q[-1][1] - 1 if q else N-1
        right.append(max(0, st.query(i+1, j) - presum[i+1]))
        st.update(i, presum[i+1])
        q.append((v, i))
    right = right[::-1]
    
    # print(left)
    # print(right)
    
    return max([a+b for a, b in zip(left, right)])

N = int(input())
A = [int(x) for x in input().split()]
# N = 10
# A = [-1 for _ in range(N)]
print(solve(N, A))
