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 C# (judge verdict: Wrong Answer)

using System;
using System.Collections.Generic;
using System.Linq;

class Program {
    static string ReadLine() { return Console.ReadLine(); }
    static int ReadInt() { return int.Parse(ReadLine()); }
    static int[] ReadInts() { return ReadLine().Split().Select(int.Parse).ToArray(); }
    static string[] ReadStrings() { return ReadLine().Split(); }

    static int MaxSumSequence(int[] xs) {
        var dp = new int[xs.Length];
        dp[0] = xs[0];
        int ans = dp[0];
        for (int i = 1; i < xs.Length; i++) {
            dp[i] = Math.Max(dp[i-1] + xs[i], xs[i]);
            ans = Math.Max(ans, dp[i]);
        }
        return ans;
    }

    static void Main() {
        int n;
        while ((n = ReadInt()) != 0) {
            var xs = new int[n];
            for (int i = 0; i < n; i++) {
                xs[i] = ReadInt();
            }
            Console.WriteLine(MaxSumSequence(xs));


            if (true) break;
        }
    }
}