import sys

n = list(map(int,input().split()))[0]
arr = list(map(int,input().split()))
dp = []

for i in range(n):
    if i ==0:
        dp.append(arr[i])
    else:
        dp.append(max(arr[i],(dp[i-1]+arr[i])))

print(max(dp))

思路挺难想，代码挺简单