#!/usr/local/bin/perl 

open CHITIN , ">CHITIN"; 
my @chars = ('A','D',); 
my $string = join '', map $chars rand @chars , 1 .. 100; $den =('DA'); 
$count=$DA; 
if ($string =~/$den/) { 
  print "DA was found \n\n"; 
} else { 
  print "DA is not present\n\n\n"; 
} 
print $count; 
print $string;