my %charCount;
        while ( my $line = <$DAT> ) {
                my @letters = $line =~ /[a-zA-Z]/g;
                foreach my $char ( @letters ) {
                        $charCount{ $char }++;
                }
        }

        foreach my $char ( keys %charCount ) {
                print "$char => $charCount{$char}\n";
        }