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: Wrong Answer)

import scala.io.StdIn._

object Main {
  def main(args: Array[String]): Unit = {
    while (true) {
      val n = readInt
      if (n == 0) return
      var sum = 0
      var max = Int.MinValue
      for (i <- 0 until n) {
        val x = readInt
        sum += x
        if (sum < 0) {
          sum = 0
        }
        max = Math.max(max, sum)
      }
      println(max)
    }
  }
}