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 Control.Applicative
import Data.List

main = do
  n <- readLn :: IO Int
  when (n /= 0) $ do
    xs <- input n read :: IO [Int]
    print $ solve xs
    main
    
solve :: [Int] -> Int
solve (x:xs) = mss [x] xs

mss :: [Int] -> [Int] -> Int
mss ls [] = maximum ls
mss ls (x:xs) | w > x = mss (w:ls) xs
              | otherwise = mss (x:ls) xs
  where
    w = head ls + x

input :: Int -> (String -> a) -> IO [a]
input n f = map f <$> replicateM n getLine