#include <bits/stdc++.h>
using namespace std;
int maxSubArraySum(int a[], int size) {
  int max_so_far = INT_MIN, max_ending_here = 0;
  for (int i = 0; i < size; i++) {
    max_ending_here = max_ending_here + a[i];
    if (max_so_far < max_ending_here) max_so_far = max_ending_here;
    if (max_ending_here < 0) max_ending_here = 0;
  }
  return max_so_far;
}
int main() {
  int n;
  cin >> n;
  int arr[n];
  int ar[n];
  int sum = 0;
  for (int i = 0; i < n; i++) {
    cin >> arr[i];
    if (arr[i] == 0) {
      ar[i] = 1;
    } else {
      ar[i] = -1;
    }
    sum += arr[i];
  }
  int a = maxSubArraySum(ar, n);
  cout << a + sum;
}
