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)

/*
	0022:Maximum Sum Sequence
*/
#include	<iostream>
#include	<algorithm>

using namespace std;

int intervalSum(int cs[], int a, int b);

int main(void) {
	while(1) {
		int n, ans;
		int array[5000], cumsum[5000] = { 0 };
		
		cin >> n;
		if(n == 0) { break; }
		
		for(int i = 0; i < n; i++) {
			cin >> array[i];
			if(i == 0) { cumsum[i] = array[i]; }
			else { cumsum[i] = array[i] + cumsum[i-1]; }
		}
		
		for(int i = 0; i < n; i++) {
			for(int j = i; j < n; j++) {
				int fl;
				if(i == j) {
					fl = array[i];
				} else if(i == 0) {
					fl = cumsum[j];
				} else {
					fl = intervalSum(cumsum, i, j);
				}
				ans = max(ans, fl);
			}
		}
		
		cout << ans << endl;
	}
	
	return 0;
}

int intervalSum(int cs[], int a, int b) {
	return cs[b] - cs[a-1];
}