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 Ruby (judge verdict: Time Limit Exceeded)

loop{
  n=gets.chomp.to_i
  break if n.zero?
  arr=[]
  n.times{arr.push gets.to_i}
  max=0
  arr.length.times do|i|
    i.upto(arr.length) do|j|
      $_=arr[i..j].inject(:+)
      max=$_ if max < $_
    end
  end 
  p max
}