#include<iostream>
using namespace std;
int main(){
	int n;
	cin>>n;
	int Arr[n],s[n];
	int sm=0;
	for(int i=0;i<n;i++){
	cin>>Arr[i];
	sm+=Arr[i];
	s[i]=sm;
}
	int Brr[n];
	int temp=0;
	for(int j=n-1;j>=0;j--)
	{
		Brr[j]=temp;
		//cout<<temp<<"\t";
		temp+=Arr[j];
	}
	int sum,max=0;
	int Crr[n];
	for(int i=n-1;i>=0;i--){
		sum+=(Arr[i]*Brr[i]);
	Crr[i]=sum;
	}
	int sj=0,sf=0,cm=0;
	for(int i=0;i<n;i++){
		for(int j=i+1;j<n;j++){
			if(i!=0)
			sj=s[j]-s[i-1];
			else
			sj=s[j]-0;
			
			sf=s[n-1]-s[j];
		
		if(Crr[i]-sj*sf>cm)
		cm=Crr[i]-sj*sf;
			
			
		}
	}
	
	
	cout<<cm<<endl;
	
	
	return 0;
}