#include <math.h>
#include <stdio.h>
#include <string.h>
#include <stdlib.h>
#include <assert.h>
#include <limits.h>
#include <stdbool.h>
int start=0,end=0;
void maxSm(int a[], int size)
{
    int max_so_far = INT_MIN, max_ending_here = 0,
        s=0;
 
    for (int i=0; i< size; i++ )
    {
        max_ending_here += a[i];
 
        if (max_so_far < max_ending_here)
        {
            max_so_far = max_ending_here;
            start = s;
            end = i;
        }
 
        if (max_ending_here < 0)
        {
            max_ending_here = 0;
            s = i + 1;
        }
    }
    
}
long int largestValue(int n, int* a) {
    // Return the largest value of any of A's nonempty subarrays.
    long long i,j,s=0;
    for(i=start;i<=end;i++)
    {
        for(j=i+1;j<=end;j++)
            s+=(a[i]*a[j]);
    }
    return s;
}

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]);
    }
    maxSm(A,n);
    long int result = largestValue(n, A);
    printf("%ld\n", result);
    return 0;
}