pku 2593

#include <iostream>
using namespace std;

int a[100001],l[100001],r[100002];
int main()
{
    int n,sum,max;
    while(1)
    {
        scanf("%d",&n);
        if(n==0)
            break;
        l[0] = -10001;
        sum = 0;
        for(int i=1;i<=n;++i)
        {
            scanf("%d",&a[i]);
            if(l[i-1] > a[i]+sum)
                l[i]=l[i-1];
            else
                l[i]=a[i]+sum;
            sum+=a[i];
            if(sum<0)
                sum=0;
        }
        r[n+1] = -10001;
        sum = 0;
        max = -200000;
        for( i=n;i!=0;--i)
        {
            if(r[i+1] > a[i]+sum)
                r[i]=r[i+1];
            else
                r[i]=a[i]+sum;
            sum+=a[i];
            if(sum<0)
                sum=0;
            if(l[i]+r[i+1]>max)
                max = l[i]+r[i+1];
        }
        printf("%d/n",max);
    }
    return 0;
}