#include <iostream>

 #include <vector>

 #include <algorithm>

 #include <queue>

 #include <stack>

 #include <string>

 #include <fstream>

 #include <map>

 using namespace std;

 bool allneg(int arr[], int n) {

     for (int i = ; i < n; i++) {

         if (arr[i] > ) return false;

     }

     return true;

 }

 int maxsum(int arr[], int n) {

     int tmp = ;

     int ans = INT_MIN;

     for (int i = ; i < n; i++) {

         tmp += arr[i];

         ans = max(ans, tmp);

         tmp = max(tmp, );

     }

     return ans;

 }

 int maxcircular(int arr[], int n) {

     int ans = maxsum(arr, n);

     if (allneg(arr, n)) return ans;

     int sum = ;

     for (int i = ; i < n; i++) {

         sum += arr[i];

         arr[i] = -arr[i];

     }

     return max(ans, sum + maxsum(arr, n));

 }

 int main() {

     int arr[] = {, , -, , -, -, , -, };

     cout << maxcircular(arr, ) << endl;

     return ;

 }