Time Limit : sec, Memory Limit : KB

# 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