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: Accepted)

#!/usr/local/bin/ruby
while (n=gets.to_i)!=0
  rec=Array.new
  for i in 1..n
    rec << gets.to_i
  end
  ans = -1000000
    for x in 1..n
    sum = 0
    for y in (x-1)..n
      sum = sum + rec[y].to_i
      if sum > ans
        ans = sum
      end
    end
  end
  puts "#{ans}"
end