G'day kanikas16,

Welcome to the Monastery.

I expect you just need split and splice:

#!/usr/bin/env perl -l

use strict;
use warnings;

my $data = '1 1 0 0 0 0 0 0 0 0 1 0 0 0 0 0 0 0 2 1 1 0 0 0 0 0 1 1 0 
+0 0 1 0 0 0 1 3 1 1 1 0 0 0 0 0 0 1 0 0 0 0 0 0 0 4 1 1 1 0 0 0 0 0 0
+ 1 0 0 0 0 0 1 0 5 1 1 0 0 0 0 0 1 1 0 0 0 1 0 0 0 1 6 1 1 0 0 0 0 0 
+1 1 0 0 0 1 0 0 0 1 7 1 1 0 1 0 0 0 0 0 1 0 0 0 0 0 0 0 8 1 1 0 0 0 0
+ 0 1 1 0 0 0 1 0 0 0 1 9 1 1 0 0 1 0 0 0 0 1 0 0 0 0 0 0 0 10 1 1 0 0
+ 0 0 0 1 1 0 0 0 1 0 0 0 1 11 1 1 0 0 0 1 0 0 0 1 0 0 0 0 0 0 0 12 1 
+1 0 0 0 0 0 1 1 0 0 0 1 0 0 0 1 13 1 1 0 0 0 0 1 1 1 1 0 0 0 0 0 0 0'
+;

my $sep = 'x' x 35; 

my @bits = split / /, $data;

print "@{[ splice @bits, 0, 18 ]}\n$sep" while @bits;
[download]

Output:

1 1 0 0 0 0 0 0 0 0 1 0 0 0 0 0 0 0
xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx
2 1 1 0 0 0 0 0 1 1 0 0 0 1 0 0 0 1
xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx
3 1 1 1 0 0 0 0 0 0 1 0 0 0 0 0 0 0
xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx
4 1 1 1 0 0 0 0 0 0 1 0 0 0 0 0 1 0
xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx
5 1 1 0 0 0 0 0 1 1 0 0 0 1 0 0 0 1
xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx
6 1 1 0 0 0 0 0 1 1 0 0 0 1 0 0 0 1
xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx
7 1 1 0 1 0 0 0 0 0 1 0 0 0 0 0 0 0
xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx
8 1 1 0 0 0 0 0 1 1 0 0 0 1 0 0 0 1
xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx
9 1 1 0 0 1 0 0 0 0 1 0 0 0 0 0 0 0
xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx
10 1 1 0 0 0 0 0 1 1 0 0 0 1 0 0 0 1
xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx
11 1 1 0 0 0 1 0 0 0 1 0 0 0 0 0 0 0
xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx
12 1 1 0 0 0 0 0 1 1 0 0 0 1 0 0 0 1
xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx
13 1 1 0 0 0 0 1 1 1 1 0 0 0 0 0 0 0
xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx
[download]

[Note: I saw your original post but ignored it because the data formats couldn't be accurately discerned (no <code>...</code> tags). I've now replied, days later, as the formatting has been fixed. Follow the guidelines in "How do I post a question effectively?" to get faster and better responses.]