# variation with grep
@a=qw(abc def ghi jkl mno pqr stu vwxyz); 
@g = grep /i/../u/, @a; 
for (1..$#g-1) { 
  print "$g[$_]\n"; 
}

# with map
@a=qw(abc def ghi jkl mno pqr stu vwxyz); 
$flag=-1; 
sub go {
  print "$_\n" if ($flag>0); 
  if ($_ =~ /i|u/) {
    $flag = $flag * -1
  }
} 
@g = map{ &go($_) => $_ } @a;