#!/usr/bin/perl

use strict; # https://perlmonks.org/?node_id=11146218
use warnings;

my $want = 8;

for ( 1 .. 24 )
  {
  my $string = 'f' x $_;
  my $padded = $string . 0 x ( - length($string) % $want );
  printf "%25s => %s\n", $string, $padded;
  }