@sorted = map { $_->[0] }
          sort { $a->[1] <=> $b->[1] ||
                 $a->[2] <=> $b->[2] ||
                 $a->[3] cmp $b->[3] ||
                 $a->[4] cmp $b->[4] }
          map { [ $_, split(/\./, $_) ] } @lines;