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)

# coding: utf-8

def max_sum_seq
  loop do
    n = gets.chomp.to_i
    break if n == 0

    array = read(n)
    candidates = []
    n.times do |i|
      (i..n-1).each do |j|
        sum = 0
        (i..j).each do |k|
          sum += array[k]
        end
        candidates << sum
      end
    end
    max = find_max(candidates)
    puts max
  end
end

def find_max(array)
  max = -10000
  array.each do |a|
    if max < a then
      max = a
    end
  end
  max
end

def read(n)
  array = []
  (0..n-1).each do
    array << gets.chomp.to_i
  end
  array
end

max_sum_seq