perl -e "@list = grep{$_ ne 'aardvark'} 
                 map{defined $_ ? $_ : 'undef'} 
                 map{$p ne $_ ? $p = $_ : 'aardvark'} 
        (qw(a a b b c 0 c u u), (undef, undef), qw(0 0 v v w w)); 
print join ' ', @list;"

Prints --> a b c 0 c u undef 0 v w