https://www.acmicpc.net/problem/1912
n = int(input())
arr = list(map(int, input().split()))
dp = [0 for _ in range(n)]
for i in range(0, n):
if i == 0:
dp[i] = arr[i]
else:
if dp[i-1]+arr[i] > 0:
dp[i] = dp[i-1]+arr[i]
else:
dp[i] = 0
if max(arr) < 0: print(max(arr))
else: print(max(dp))