#!/usr/bin/perl

use strict; # https://perlmonks.org/?node_id=11146507
use warnings;

for my $n ( 24, 25, 26 )
  {
  my $favorites = join '~~~', map "a|||b|||$_", 1 .. $n;

  my $favnums = join '',
    reverse map ',' . (split /\|{3}/ )[2],
    grep defined,
    ( split /~~~/, $favorites, 26 )[0 .. 24];

  print "n = $n\n\n$favorites\n\n$favnums\n\n";
  }