#!/usr/bin/perl -w
use strict;
use Data::Dumper;

## version 1....
my $num =0;
my %h = map{$_, $num++}('A'..'Z','a'..'z'); 
print Dumper \%h;

## version 2...
my %hash;
foreach my $letter (('A'..'Z','a'..'z'))
{
   $hash{$letter}++;
}
print Dumper \%hash;

foreach (sort keys %h)
{
   print "$_ OK\n" if $hash{$_};
}