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: Wrong Answer)

import Control.Monad
import Data.Array

main = do
    n <- readLn
    unless (n==0) $ do
                  list <- replicateM n readLn
                  print $ mss2 0 0 list
                  main

mss2 :: Int -> Int -> [Int] -> Int
mss2 mx _ []  = mx 
mss2 mx locSum (x:xs)
    | thisSum > mx = mss2 thisSum thisSum xs
    | thisSum < 0  = mss2 mx 0 xs
    | otherwise    = mss2 mx thisSum xs
    where thisSum = locSum + x