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)

//O(n^2)
#include<stdio.h>
#include<math.h>

long long n,rui[10000];

long long max( long long x,long long y ){
	if( x > y )
		return x;
	return y;
}

int main()
{
	long long i,j;
	long long ans;
	while( scanf("%lld",&n) != EOF )
	{
		if( n == 0 )break;
		ans = 0;
		for( i = 0;i < n;i++ ){
			scanf("%lld",rui+i );
			if( i )rui[i] += rui[i-1];
		}
		
		for( i = 0;i < n;i++ ){
			for( j = i;j < n;j++ ){
				if( i )
					ans = max( ans, rui[j]-rui[i-1] );
				else
					ans = max( ans,rui[j] );
			}
		}
		
		printf("%lld\n",ans);
	}
	return 0;
}