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():
    from sys import stdin
    f_i = stdin
    
    while True:
        n = int(f_i.readline())
        if n == 0:
            break
        
        ans = int(f_i.readline())
        s = ans
        for i in range(n - 1):
            if s > 0:
                s += int(f_i.readline())
            else:
                s = int(f_i.readline())
            if s > ans:
                ans = s
        print(ans)

solve()