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)

n = gets.to_i
while n != 0 do
	max = -999999
	a = Array.new(n,0)
	n.times do |i|#input data
		a[i] = gets.to_i
		max = a[i] if a[i] > max
	end

	n.times do |i|#calc sum
		ans = a[i]
		(n-i-1).times do |j|
			ans = a[j+i+1] + ans
			max = ans if max < ans 
		end
	end
	puts max
	n = gets.to_i
end