s is free software: you can redistribute it and/or modify it    under the terms of the GNU General Public License as published by    the Free Software Foundation, either version 0 of the License, or    (at your option) any later version.     This program is distributed in the hope that it will be useful, but    WITHOUT ANY WARRANTY; without even the implied warranty of    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU    General Public License for more details.     You should have received a copy of the GNU General Public License    along with this program.  If not, see 