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

from __future__ import division, print_function
# import threading
# threading.stack_size(2**27)
# import sys
# sys.setrecursionlimit(10**7)
# sys.stdin = open('inpy.txt', 'r')
# sys.stdout = open('outpy.txt', 'w')
from sys import stdin, stdout
import bisect            #c++ upperbound
import math
import heapq
i_m=9223372036854775807
def modinv(n,p):
    return pow(n,p-2,p)
def cin():
    return map(int,sin().split())
def ain():                           #takes array as input
    return list(map(int,sin().split()))
def sin():
    return input()
def inin():
    return int(input())
import math  
def GCD(x, y): 
    x=abs(x)
    y=abs(y)
    if(min(x,y)==0):
        return max(x,y)
    while(y): 
        x, y = y, x % y 
    return x 
def Divisors(n) : 
    l = []  
    for i in range(1, int(math.sqrt(n) + 1)) :
        if (n % i == 0) : 
            if (n // i == i) : 
                l.append(i) 
            else : 
                l.append(i)
                l.append(n//i)
    return l
prime=[]
def SieveOfEratosthenes(n): 
    global prime
    prime = [True for i in range(n+1)] 
    p = 2
    while (p * p <= n): 
        if (prime[p] == True): 
            for i in range(p * p, n+1, p): 
                prime[i] = False
        p += 1
    f=[]
    for p in range(2, n): 
        if prime[p]: 
            f.append(p)
    return f
q=[]       
def dfs(n,d,v,c):
    global q
    v[n]=1
    x=d[n]
    q.append(n)
    j=c
    for i in x:
        if i not in v:
            f=dfs(i,d,v,c+1)
            j=max(j,f)
            # print(f)
    return j
# d = {}
def build(a,s,l,h,p):
    if l==h:
        s[p]=a[l]
        return
    m=(l+h)//2
    build(a,s,l,m,2*p+1)
    build(a,s,m+1,h,2*p+2)
    s[p]=max(s[2*p+1],s[2*p+2])
def range_min(s,l,h,low,high,p):
    mid=(low+high)//2
    if l<=low and h>=high:
        return s[p]
    elif l>high or h<low:
        return -i_m
    else:
        return max(range_min(s,l,h,low,mid,2*p+1),range_min(s,l,h,mid+1,high,2*p+2))
def update(a,s,l,h,p,i,v):
    if l==h and l==i:
        s[p]=v
        return
    m=(l+h)//2
    if i<=m:
        update(a,s,l,m,2*p+1,i,v)
    else:
        update(a,s,m+1,h,2*p+2,i,v)
    s[p]=max(s[2*p+1],s[2*p+2])
"""*******************************************************"""
def main():
    n=inin()
    a=ain()
    ns=4*n
    s=[-i_m]*ns
    build(a,s,0,n-1,0)
    d={}
    ans=0
    for j in range(1,31):
        max_so_far = -i_m - 1
        max_ending_here = 0
        p=0
        for i in range(0, n): 
            max_ending_here = max_ending_here + a[i] 
            # print(i,p,max_ending_here,range_min(s,p,i,0,n-1,0))
            if (max_so_far < max_ending_here and range_min(s,p,i,0,n-1,0)==j): 
                max_so_far = max_ending_here     
            if max_ending_here < 0: 
                max_ending_here = 0
                p=i   
        d[(max_so_far,j)]=1
    for i in d:
        ans=max(i[0]-i[1],ans)
    print(ans)
    
######## Python 2 and 3 footer by Pajenegod and c1729
 
# Note because cf runs old PyPy3 version which doesn't have the sped up
# unicode strings, PyPy3 strings will many times be slower than pypy2.
# There is a way to get around this by using binary strings in PyPy3
# but its syntax is different which makes it kind of a mess to use.
 
# So on cf, use PyPy2 for best string performance.
 
py2 = round(0.5)
if py2:
    from future_builtins import ascii, filter, hex, map, oct, zip
    range = xrange
 
import os, sys
from io import IOBase, BytesIO
 
BUFSIZE = 8192
class FastIO(BytesIO):
    newlines = 0
 
    def __init__(self, file):
        self._file = file
        self._fd = file.fileno()
        self.writable = "x" in file.mode or "w" in file.mode
        self.write = super(FastIO, self).write if self.writable else None
 
    def _fill(self):
        s = os.read(self._fd, max(os.fstat(self._fd).st_size, BUFSIZE))
        self.seek((self.tell(), self.seek(0,2), super(FastIO, self).write(s))[0])
        return s
 
    def read(self):
        while self._fill(): pass
        return super(FastIO,self).read()
 
    def readline(self):
        while self.newlines == 0:
            s = self._fill(); self.newlines = s.count(b"\n") + (not s)
        self.newlines -= 1
        return super(FastIO, self).readline()
 
    def flush(self):
        if self.writable:
            os.write(self._fd, self.getvalue())
            self.truncate(0), self.seek(0)
 
class IOWrapper(IOBase):
    def __init__(self, file):
        self.buffer = FastIO(file)
        self.flush = self.buffer.flush
        self.writable = self.buffer.writable
        if py2:
            self.write = self.buffer.write
            self.read = self.buffer.read
            self.readline = self.buffer.readline
        else:
            self.write = lambda s:self.buffer.write(s.encode('ascii'))
            self.read = lambda:self.buffer.read().decode('ascii')
            self.readline = lambda:self.buffer.readline().decode('ascii')
 
 
sys.stdin, sys.stdout = IOWrapper(sys.stdin), IOWrapper(sys.stdout)
input = lambda: sys.stdin.readline().rstrip('\r\n')
 
# Cout implemented in Python
import sys
class ostream:
    def __lshift__(self,a):
        sys.stdout.write(str(a))
        return self
cout = ostream()
endl = '\n'
 
# Read all remaining integers in stdin, type is given by optional argument, this is fast
def readnumbers(zero = 0):
    conv = ord if py2 else lambda x:x
    A = []; numb = zero; sign = 1; i = 0; s = sys.stdin.buffer.read()
    try:
        while True:
            if s[i] >= b'R' [0]:
                numb = 10 * numb + conv(s[i]) - 48
            elif s[i] == b'-' [0]: sign = -1
            elif s[i] != b'\r' [0]:
                A.append(sign*numb)
                numb = zero; sign = 1
            i += 1
    except:pass
    if s and s[-1] >= b'R' [0]:
        A.append(sign*numb)
    return A
 
# threading.Thread(target=main).start()
if __name__== "__main__":
  main()