import java.io.*;
import java.util.*;
import java.text.*;
import java.math.*;
import java.util.regex.*;

public class Solution {

    static BigInteger largestValue(int[] A,int I, int J) {
        BigInteger sum1 = new BigInteger("0");
        BigInteger sum2 = new BigInteger("0");
        for(int i = I; i <= J; i++){
            sum1=sum1.add(new BigInteger(Integer.toString(A[i])));
            sum2=sum2.add(new BigInteger(Integer.toString(A[i]*A[i])));
        }
        sum1=sum1.pow(2);
        sum1=sum1.subtract(sum2);
        sum1=sum1.divide(new BigInteger("2"));
        return sum1;
    }

    public static void main(String[] args) {
        Scanner in = new Scanner(System.in);
        int n = in.nextInt();
        int[] A = new int[n];
        int[] A2 = new int[n];
        for(int A_i = 0; A_i < n; A_i++){
            A[A_i] = in.nextInt();
            A2[A_i] = A[A_i]*A[A_i];
        }

        int max_so_far = Integer.MIN_VALUE, max_ending_here = 0;
 
        int I = 0;
        int J = 0;
        for (int i = 0; i < A.length; i++)
        {
            max_ending_here = max_ending_here + A[i];
            if (max_so_far < max_ending_here){
                max_so_far = max_ending_here;
                J = i;
            }
            if (max_ending_here < 0){
                max_ending_here = 0;
                I=i+1;
            }
        }
        BigInteger result = largestValue(A,I,J);
        System.out.println(result);
        in.close();
    }
}