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 Haskell (judge verdict: Accepted)

import Control.Monad
import Data.Functor
import System.IO

minVal = minBound :: Int

main = do
  n <- readInt <$> getLine
  if n == 0 then return () else do
    xs <- replicateM n (readInt <$> getLine)
    print $ solve xs
    main

solve :: [Int] -> Int
solve = loop minVal 0
  where loop v _ [] = v
        loop v s (x:xs) = loop (max v w) w xs
          where w = max (s + x) x

readInt :: String -> Int
readInt = read