#include <fstream>
#include <iostream>
#include <algorithm>
# define N 100005
using namespace std;
ifstream fin(".in");
ofstream fout(".out");
/// metoda greedy = lacom
/**
var 1: calc min1, min2 si max1 max 2 si camparam cele 2 produse
var 2: sortam vector cresc  se compara prod primelor 2 valori si a ultimelor 2 valori
*/

int n, a[N];
///var 2
void Citire()
{
    cin>>n;
    for(int i=1;i<=n;i++)
        cin>>a[i];
}
void Greedy()
{
    sort(a+1, a+n+1);///STL
    cout<<max(a[1]*a[2], a[n]*a[n-1]);
}

int main()
{
  Citire();
  Greedy();
  return 0;
}