use warnings; use strict;

use List::Util qw[ max ];

my %p =
  ( 'a' => 1
  , 'm l n o p q' => 20
  , 'x y z' => 321
  );

my $name = max map { length $_ } keys %p;
my $number = max map { length $_ } values %p;

my $format = "%-${name}s  %${number}d\n\n";

my $out = '';
for ( sort keys %p )
{
  $out .= sprintf $format , $_ , $p{ $_ }
}
print $out;