#include <math.h>
#include <stdio.h>
#include <string.h>
#include <stdlib.h>
#include <assert.h>
#include <limits.h>
#include <stdbool.h>
int l,r;
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;
            r=i;
        }
 
        if (max_ending_here < 0)
        { max_ending_here = 0;
            l=i+1;
        }
    }
  //  printf("%d %d\n",l,r);
  //  printf("%d\n", max_so_far);
    return max_so_far;
}
long int largestValue(int A_size, int* A) {
    maxSubArraySum(A,A_size);
    long long int prod=0;
    for(int i=l;i<=r;i++)
    {
        for(int j=i+1;j<=r;j++)
        {
       //     printf("%d ",A[i]*A[j]);
            prod+=A[i]*A[j];
        }
    }
    return prod;
    // Return the largest value of any of A's nonempty subarrays.
}


int main() {
    int n; 
    scanf("%i", &n);
    int *A = malloc(sizeof(int) * n);
    for (int A_i = 0; A_i < n; A_i++) {
       scanf("%i",&A[A_i]);
    }
    long int result = largestValue(n, A);
    printf("%ld\n", result);
    return 0;
}