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)

$debug=0
def main
  dat=[]
  fh=STDIN
  #fh=File.new("x.txt", "r")
  while fh.gets
    n=$_.chomp.to_i
    break if n==0

    max= -9999999
    subseq = []

    n.times {
      a = fh.gets.chomp.to_i
      subseq.map!{|x| x+= a}
      subseq.push(a)

      cmax = subseq.max
      max = cmax if cmax > max
    }
    puts max

  end
end

if $0 == __FILE__ then
  main
end