#include<iostream>
using namespace std;
int main()
{
int N, i, v, pMin, min, min2, max, max2;
cin>>N>>min>>max;
  if(min < max) {
     min2 = max; max2 = min;
  }
  else{
     min2 = min; max2 = max;
     min = max2; max = min2;
  }
  for (i = 3 ;i<= N;i++)
  {
    cin>>v;
    if (v < min){
      min2 = min; min = v;
    }
    else if (v < min2 ) min2 = v;
    if (v > max ){
      max2 = max; max = v;
    }
    else if (v > max2) max2 = v;
  }
  pMin = min*min2;
  if (max*max2 < pMin)  pMin = max*max2;
  if (max*min  < pMin) pMin = max*min;
 cout<<pMin;
 return 0;
}
/*var N, i, v, pMin, min, min2, max, max2: integer;
    neg: boolean;
begin
  readln(N);
  readln(min);
  readln(max);
  if min < max then begin
     min2 := max; max2 := min;
  end
  else begin
     min2 := min; max2 := max;
     min := max2; max := min2;
  end;
  for i := 1 to N-2 do begin
    readln(v);
    if v < min then begin
      min2 := min; min := v;
    end
    else if v < min2 then min2 := v;
    if v > max then begin
      max2 := max; max := v;
    end
    else if v > max2 then max2 := v;
  end;
  pMin := min*min2;
  if max*max2 < pMin then pMin := max*max2;
  if max*min  < pMin then pMin := max*min;
  writeln(pMin)
end.*/