#include <bits/stdc++.h>
using namespace std;
long long max(long long a, long long b) { return (a > b) ? a : b; }
long long min(long long a, long long b) { return (a < b) ? a : b; }
signed main() {
  long long t = 1;
  while (t--) {
    long long n;
    cin >> n;
    long long a[n];
    long long ans = 0, cur = 0;
    for (long long i = 0; i < n; i++) {
      cin >> a[i];
      if (a[i] == 1) cur++;
    }
    for (long long i = 0; i < n; i++) {
      for (long long j = i; j < n; j++) {
        long long rr = 0, tt = 0;
        for (long long k = i; k < j + 1; k++) {
          if (a[k] == 1)
            rr++;
          else
            tt++;
        }
        ans = max(cur - rr + tt, ans);
      }
    }
    cout << ans;
  }
}

### Prompt

Create a solution in Cpp for the following problem:

Iahub got bored, so he invented a game to be played on paper. 

He writes n integers a1, a2, ..., an. Each of those integers can be either 0 or 1. He's allowed to do exactly one move: he chooses two indices i and j (1 ≤ i ≤ j ≤ n) and flips all values ak for which their positions are in range [i, j] (that is i ≤ k ≤ j). Flip the value of x means to apply operation x = 1 - x.

The goal of the game is that after exactly one move to obtain the maximum number of ones. Write a program to solve the little game of Iahub.

Input

The first line of the input contains an integer n (1 ≤ n ≤ 100). In the second line of the input there are n integers: a1, a2, ..., an. It is guaranteed that each of those n values is either 0 or 1.

Output

Print an integer — the maximal number of 1s that can be obtained after exactly one move. 

Examples

Input

5
1 0 0 1 0


Output

4


Input

4
1 0 0 1


Output

4

Note

In the first case, flip the segment from 2 to 5 (i = 2, j = 5). That flip changes the sequence, it becomes: [1 1 1 0 1]. So, it contains four ones. There is no way to make the whole sequence equal to [1 1 1 1 1].

In the second case, flipping only the second and the third element (i = 2, j = 3) will turn all numbers into 1.

### Response

```cpp
#include <bits/stdc++.h>
using namespace std;
long long max(long long a, long long b) { return (a > b) ? a : b; }
long long min(long long a, long long b) { return (a < b) ? a : b; }
signed main() {
  long long t = 1;
  while (t--) {
    long long n;
    cin >> n;
    long long a[n];
    long long ans = 0, cur = 0;
    for (long long i = 0; i < n; i++) {
      cin >> a[i];
      if (a[i] == 1) cur++;
    }
    for (long long i = 0; i < n; i++) {
      for (long long j = i; j < n; j++) {
        long long rr = 0, tt = 0;
        for (long long k = i; k < j + 1; k++) {
          if (a[k] == 1)
            rr++;
          else
            tt++;
        }
        ans = max(cur - rr + tt, ans);
      }
    }
    cout << ans;
  }
}

```