my $string = 'abcijuwegwegwglwjgwgwhgwkgjnwgkjwngwnmgioghwoöighwghwgökwnglkwhgwohgwelökgnwgklweghgweghwelg,wngwehgwhgweoöhgwegnjwegnwegmwgega';

sub MAXSIZE { 13 };

my @parts = ();
my $cur = 0;

while ($cur < length($string)) {
        push @parts, substr($string, $cur, MAXSIZE);
        $cur += MAXSIZE;
}

say "@parts";