Arr1      Arr2
3         4
5         5
6         6
8         10

##</code><code>##

File-arr1-1.txt
arr1[0], arr1[1], arr1[2]

File-arr2-1.txt
arr2[0], arr2[1], arr2[2], arr2[3]

File-arr1-2.txt
arr1[3]

File-arr2-2.txt
arr2[4]

File-arr1-3.txt
arr1[4]

File-arr2-3.txt
---

File-arr1-4.txt
arr1[5]

File-arr2-4.txt
arr2[5]

File-arr1-5.txt
arr1[6]

File-arr2-5.txt
arr2[6]

File-arr1-6.txt
arr1[7]

File-arr2-6.txt
arr2[7], arr2[8], arr2[9]

File-arr1-7.txt
arr1[8]

File-arr2-8.txt
arr2[10]

##</code><code>##

my $start = 0;
my $end = 0;


for my $i (0 .. $#al) {
	$end = $al[$i][0];
	for my $s ($start .. $end-1){
		print "$start\t$end\n";

		if ($s == $end-1){
			$start = $end+1;
		}
	}

}