Problem:
Maximum Sum Sequence

Given a sequence of numbers a1, a2, a3, ..., an, find the maximum sum of a contiguous subsequence of those numbers. Note that, a subsequence of one element is also a contiquous subsequence.

Input

The input consists of multiple datasets. Each data set consists of:

n
a1
a2
.
.
an

You can assume that 1 ≤ n ≤ 5000 and -100000 ≤ ai ≤ 100000.

The input end with a line consisting of a single 0.

Output

For each dataset, print the maximum sum in a line.

Sample Input

7
-5
-1
6
4
9
-6
-7
13
1
2
3
2
-2
-1
1
2
3
2
1
-2
1
3
1000
-200
201
0

Output for the Sample Input

19
14
1001

Solution in Python3 (judge verdict: Accepted)



def solve(a_list):
    if len(list(filter(lambda x: x >= 0, a_list))) == 0:
        return max(a_list)

    dp = [0] * len(a_list)
    dp[0] = a_list[0]
    for i in range(1, len(dp)):
        dp[i] = max(a_list[i], a_list[i] + dp[i - 1])
    return max(dp)


def main():
    while True:
        n = int(input())
        if n == 0:
            break
        a_list = [int(input()) for _ in range(n)]
        print(solve(a_list))


if __name__ == '__main__':
    main()