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: Time Limit Exceeded)

main(){
  int a[5000],i,j,k,l,n,s,t;
  for(;;){
    scanf("%d",&n);
    if(n==0)
      break;
    for(i=0;i<n;i++)
      scanf("%d",&a[i]);
    for(l=0;a[l]<0;l++)
      n--;
    t=0;
    for(i=1;i<=n;i++)
      for(j=l;j<=n-i+l;j++){
	s=0;
	for(k=0;k<i;k++)
	  s+=a[j+k];
	if(s>t)
	  t=s;
      }
    printf("%d\n",t);
  }
  return 0;
}