%combinations = ( 
          co1 => [
                  [ qw(one two three four five) ],
                  [ qw(one one two three five) ]
                 ], 
          co2 => [
                  [ qw(one two three five seven) ],
                  [ qw(one one two three five) ]
                 ],
          co3 => [
                  [ qw(one two three five seven) ],
                  [ qw(one two three four five) ]
                 ],
          co4 => [
                  [ qw(one two three five seven) ],
                  [ qw(one two three four five) ],
                  [ qw(one one two three five) ]
                 ],
          us1 => [ qw(one two three four five) ],
          us2 => [ qw(one two three five seven) ],
          us3 => [ qw(one one two three five) ],
          );