use strict;
use warnings;

my @original_names =
(
    'Fred Flintstone',
    'Leonardo da Vinci ',
    'Raffaello da Urbino',
);

my @cognome = last_name_first(@original_names);

print join(';', @cognome);

sub last_name_first
{
    my @names = @_;

    for (@names)
    {
        s/\s+$//;
        s/^(.*?)(\S+)$/$2, $1/;
        s/\s+$//;
    }

    return @names;
}