use List::Util 'shuffle';

my @bag = shuffle qw( A B C D E );
my @embargoed = pop @bag;

while ( 1 ) {
   my $time = ( localtime )[ 0 ]; # seconds
   sleep 1;
   if ( $time >= 55 ) {
	 push @embargoed, pop @bag;
	 push @bag, shift @embargoed if @embargoed > 2;
	 @bag = shuffle @bag;
	 sleep 5;
  }
  print "$time @embargoed\n";
}