Gnat storage size

[tmoran@acm.org]

What command line parameter do I need with Gnat 3.15p to increase the
main program's stack size?  I'm getting
raised STORAGE_ERROR : big.adb:4 object too large
when the command line parameter is >= 4026 with the program:
with ada.command_line;
procedure big is
  procedure try(k : in integer) is
    x : array(1 .. k*1042) of integer;
  begin
    x(1) := 0;
  end try;
begin
  try(integer'value(ada.command_line.argument(1)));
end big;