TICHMAX PASCAL

var max1,max2,max3,min1,min2,x,i,n:longint;
    kq:int64;
 
function maxx(a,b:longint):longint;
begin
    if a>b then exit(a) 
    else exit(b);
end;
 
procedure nhap()
begin
    readln(n);
    for i:=1 to n do read(a[i]);
end;
 
procedure tim_max;
begin
    max1:=-maxlongint;
    max2:=max1;
    max3:=max1;
    for i:=1 to n do 
    begin
        if (a[i]>=max1) then
        begin
            max3:=max2;
            max2:=max1;
            max1:=a[i];
         end 
         else 
            if (a[i]>=max2) then
            begin
                max3:=max2;
                max2:=a[i];
            end 
            else 
                if (a[i]>=max3) then
                    max3:=a[i];
end;
 
procedure tim_min;
begin
    min1:=maxlongint;
    min2:=min1;
    for i:=1 to n do
    begin
        if a[i]<=min1 then
        begin
            min2:=min1;
            min1:=a[i];
        end 
        else 
            if (a[i]<=min2) then
                min2:=a[i];
    end;
end;
begin
    assign(input,'tichmax.inp');reset(input);
    assign(output,'tichmax.out');rewrite(output);
    nhap;
    tim_max;
    tim_min;
    kq:=maxx(max1*max2*max3,min1*min2*max1);
    writeln(kq);
end.