#include <algorithm>
#include <iostream>
#include <cstdlib>
#include <cstring>
#include <cstdio>
#include <string>
#include <vector>
#include <bitset>
#include <stack>
#include <cmath>
#include <deque>
#include <queue>
#include <list>
#include <set>
#include <map>
#define mem(a, b) memset(a, b, sizeof(a))
#define pi acos(-1)
using namespace std;
typedef long long ll;
const int inf = 0x3f3f3f3f;
int num[105];
int main(){
int n;
while(~scanf("%d", &n)){
int ans = 0;
for(int i= 0; i < n; i++){
scanf("%d", &num[i]);
if(num[i] == 1){
ans++;
}
}
int temp = -100;
for(int i = 0; i < n; i++){
int cnt_1 = 0, cnt_0 = 0;
for(int j = i; j < n; j++){
if(num[j] == 1){
cnt_1++;
}
else{
cnt_0++;
}
temp = max(temp, cnt_0-cnt_1);
}
}
printf("%d\n", ans+temp);
}
}