#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 ",l,r);
    return max_so_far;
}
long int largestValue(int n, int* a) 
{
    int ans=0;
    int i=maxSubArraySum(a,n);
    for(i=l;i<r;i++)
    {
        for(int j=i+1;j<=r;j++)
        {
            ans+=(a[i]*a[j]);
        }
    }
    return ans;
}
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;
}