use List::Compare;
@a = qw/AA12 BB13 CC14 DD15/;
@b = qw/AA1 AA2 AA12 BB13/;

    $element = List::Compare->new(\@a, \@b);
    #@UF = $element->get_unique;
    @CB = $element->get_intersection;

print join "\n", @CB;
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