1 -> 10, 20, 30, 40
10 -> 100, 101, 102
100 -> no data
101 -> 1011
1011 -> no data
102 -> no data

20 -> no data

30 -> 301, 302
301 -> no data
302 -> no data

40 -> 401, 402
401 -> 4011
4011 -> 40111
40111 -> no data
402 -> no data

##</code><code>##

#!/usr/bin/perl

@ini_array = ();
#input file 
open(F,"C:/test/1.txt") or die "Can't open 1.txt file";
while(<F>) {
	chomp;
	push(@ini_array,$_);
}
close F;


@final_array;
foreach $ab (@ini_array) {
	push(@final_array,$ab);
	&common($ab);
}


sub common() {
	$fl = shift;
	open(A,"C:/test/$fl.txt") or die "Can't open $fl";
		@sublist = <A>;
	close A;

	$cnt = scalar @sublist;
	if ($cnt > 0) {
		subfl(\@sublist);
	}
	else {
		push(@final_array,@sublist);
	}

}


sub subfl() {
	$arfirst = shift;
	@ini_array1 = @$arfirst;
	foreach $ab1 (@ini_array1) {
		chomp($ab1);
		push(@final_array,$ab1);
		&common($ab1);
	}
}