use Test2::V0;
use v5.40;

my @list1= qw( K B I S Y A Q );
my @list2= qw( B S N A );
my @list3= qw( Y N Q );

my $combined= fancy_algorithm(\@list1, \@list2, \@list3);
is( $combined, [qw( K B I S Y N A Q )] );

##</code><code>##

use Test2::V0;
use v5.40;

my @lists= (
  [qw( X P Y )],
  [qw( X B Y N )],
  [qw( P B N )],
  [qw( X B P N )],
  [qw( X B P Y )],
  [qw( A Z )],
  [qw( A K L )],
);

my $combined= fancy_algorithm(@lists);
is( $combined, [qw( X B P Y N A Z K L )] );