#include <iostream>
using namespace std;
int n,a[200001],aux,i;
long long p=0;
void citire()
{
    cin>>n;
    for(int i=1;i<=n;i++)
        cin>>a[i];
}

int sortare(int st, int dr)
{
    int aux,i,j,di,dj;
    di=0;dj=1;i=st;j=dr;
    while(i<j)
    {
        if(a[i]>a[j])
        {
            aux=a[i];
            a[i]=a[j];
            a[j]=aux;
            aux=di;
            di=dj;
            dj=aux;
        }
        i=i+di;
        j=j-dj;
    }
    return i;
}

void quick(int st, int dr)
{
    int x;
    if(st<dr)
    {
        x=sortare(st,dr);
        quick(st,x-1);
        quick(x+1,dr);
    }
}

void rezolva()
{
    if(n==1)
        p=a[1];
    else
    {	if((long long)a[n]*(long long)a[n-1]>(long long)a[1]*(long long)a[2])
        	p=(long long)a[n]*(long long)a[n-1];
    	else
            p=(long long)a[1]*(long long)a[2];
    }
	cout << p;
}
int main()
{
  citire();
quick(1,n);
  rezolva();
    return 0;
}