#!/usr/local/bin/perl
use strict;
use warnings;

my %seen = ();
my $string = "an apple a day";
while ($string =~ /(.)/g){
   $seen{$1}++;
}
print "unique charts are:", sort(keys %seen), "\n";

my $sum = 0;
foreach my $ascval(unpack("C*", $str)){
   $sum += $ascval;
}
print "sum is $sum\n";