use warnings;
use strict;
use Data::Dumper;

my @words;
while (<DATA>) {
    chomp;
    push @words, grep { /[^aeiouy]{4}/i } split;
}

print Dumper(\@words);

__DATA__
abc def ghi AAAAAA
jlkm
opqr jhggjyg
123 annn jkjkkj bcdefgh