c:\@Work\Perl\monks\fidda>perl -wMstrict -le
"use List::MoreUtils qw(part);
 ;;
 use constant KEYS  => qw(H1 H2 H3 H4);
 use constant ITEMS => 'A' .. 'O';
 ;;
 my @steps = map { @$_, reverse @$_ } [ 0 .. KEYS-1 ];
 ;;
 my $i = 0;
 my @parts = part { $steps[ $i++ % @steps ] } ITEMS;
 ;;
 my %h;
 @h{ KEYS() } = @parts;
 for my $k (KEYS) {
   printf qq{$k };
   printf qq{'$_' } for @{ $h{$k} };
   print '';
   }
"
H1 'A' 'H' 'I'
H2 'B' 'G' 'J' 'O'
H3 'C' 'F' 'K' 'N'
H4 'D' 'E' 'L' 'M'