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 Scala (judge verdict: Accepted)

import scala.io.StdIn.readLine

object Main {

  def loop(max:Int, sum:Int, i:Int):Int = {
    i match {
      case 0 => if( sum > max ) sum else max
      case i =>
        val m = readLine().toInt
        val (x,y) =
          if(sum < 0 && m > sum) (max,m)
          else if(m < 0 && sum > max) (sum,sum+m)
          else (max, sum+m)
        loop(x,y,i-1)
    }
  }

  def main(args: Array[String]) = {
    val b = new StringBuilder

    var n = readLine().toInt
    while(n!= 0) {
      b.append(loop(-100000, readLine().toInt, n-1).toString)
      b.append("\n")
      n = readLine().toInt
    }

    print(b.result)
  }
}