#include<iostream>
#include<climits>
using namespace std;
int a[5*100000+1];
int maxSubArraySum( int size)
{
    int max_so_far = INT_MIN, max_ending_here = 0,
       start =0, end = 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 long A=0;
    for(int i=start;i<=end;i++)
    {
        A=A+a[i]*(max_so_far-a[i]);
        max_so_far-=a[i];
    }
    cout<<A;
    return 0;
}
int main()
{
    int N;
    cin>>N;
    for(int i=0;i<N;i++)
        cin>>a[i];
    int n = sizeof(a)/sizeof(a[0]);
    int max_sum = maxSubArraySum( n);
    return 0;
}