POJ_2593_DP

#include<iostream>
#include<cstdio>
#define MIN -0x3f3f3f3f;
using namespace std;

int a[100005],lmax[100005],rmax[100005],n;

int main()
{
    while(scanf("%d",&n) && n)
    {
        lmax[0] = MIN;
        rmax[n+1] = MIN;
        for(int i = 1;i <= n;i++)    scanf("%d",&a[i]);
        int sum = 0;
        for(int i = 1;i <= n;i++)
        {
            sum += a[i];
            if(lmax[i-1] < sum)    lmax[i] = sum;
            else    lmax[i] = lmax[i-1];
            if(sum < 0)    sum = 0;
        }
        sum = 0;
        for(int i = n;i >= 1;i--)
        {
            sum += a[i];
            if(rmax[i+1] < sum)    rmax[i] = sum;
            else    rmax[i] = rmax[i+1];
            if(sum < 0)    sum = 0;
        }
        int maxx = MIN;
        for(int i = 1;i < n;i++)    maxx = max(maxx,lmax[i]+rmax[i+1]);
        printf("%d\n",maxx);
    }
    return 0;
    
}