#!/usr/bin/perl -w
use strict;
use PDL;
use List::MoreUtils qw(any);

my @a;
$a[5] = 1;

my @b = (0..8);

LOOK: for my $d (0..2) {
	my @c = @b[$d*3..$d*3+2];
	if (any { defined $a[$_] } @c) {
		print "d:$d\n" and last LOOK;
		}
	else {();}
	}