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

public class Solution {
    
    static long largestValue(int[] A) 
    {
        int size=A.length;
        long values;
        long sum;
        int i,j;
        values=A[0]*A[1];
        sum=A[0]+A[1];
        
        long largeValue=values;
        i=2;
        long sum1,sum2,values1,values2;
        j=0;
        while(i<size-1)
        {
            values1=values+sum*A[i];
            sum1=sum+A[i];
            sum2=sum1-A[j];
            values2=values1-A[j]*sum2;
            if(values1>values2)
            {
                values=values1;
                sum=sum1;
            }
            else if(values1==values2)
            {
                if(sum1>sum2)
                {
                    
                values=values1;
                sum=sum1;
                }
                else
                    {
                values=values2;
                sum=sum2;
                j++;
            }
                    
            }
            else
            {
                values=values2;
                sum=sum2;
                j++;
            }
            largeValue=largeValue>values?largeValue:values;
            i++;
        }
        return largeValue;
    }

    public static void main(String[] args) {
        Scanner in = new Scanner(System.in);
        int n = in.nextInt();
        int[] A = new int[n];
        for(int A_i = 0; A_i < n; A_i++){
            A[A_i] = in.nextInt();
        }
        long result = largestValue(A);
        System.out.println(result);
        in.close();
    }
}