use 5.010; 
use strict; 
use warnings; 
open(FILE, "<:encoding(UTF-8)", "aa.txt") or die "Could not open file: $!"; 
my $numbers; 
while (<FILE>) { 
    $numbers="$_" ; 
    print "$_"; 
} 
chomp $numbers; 
print "\n$numbers"; 
my $len=length($numbers); 
print "\n$len\n"; 
my $i; 
my $abc; 
foreach my $i (0..$len){ 
    foreach my $j (1..6) { 
        print "$j----->"; 
        $abc = substr($numbers,$i,$j); 
        print "$abc\n"; 
    } 
    print "***********************************\n"; 
} 
close FILE;