codeforces 327 A Ciel and Dancing

//cf 191 A
//2013-07-04-22.13
#include <stdio.h>
#include <string.h>
#include <algorithm>
using namespace std;
int a[105];

int cnt[105];

int main()
{
    int n;
    while (scanf("%d", &n) != EOF)
    {
        int sum = 0;
        memset(cnt, 0, sizeof(cnt));
        for (int i = 1; i <= n; i++)
        {
            scanf("%d", &a[i]);
            if (a[i] == 0)
            {
                cnt[i] = cnt[i-1] + 1;
            }
            else
            {
                cnt[i] = cnt[i-1];
                sum++;
            }
        }
        if (sum == n)
        {
            printf("%d\n", sum - 1);
            continue;
        }
        if (sum == n-1)
        {
            printf("%d\n", n);
            continue;
        }
        int ans = sum + 1;
        for (int i = 2; i <= n; i++)
        {
            for (int j = 1; j < i; j++)
            {
                if ((cnt[i] - cnt[j-1]) > ((i-j+1) - (cnt[i] - cnt[j-1])))
                    ans = max (ans, sum - ((i-j+1) - (cnt[i] - cnt[j-1])) + (cnt[i] - cnt[j-1]));
            }
        }
        printf("%d\n", ans);
    }
    return 0;
}