#!/usr/bin/perl
use strict;
use warnings;
use 5.014;

my @prot = qw/ D K /;
my ($acid_cnt, $base_cnt, $neutral_cnt);
while(@prot)
{
	my $aa = shift (@prot);
	if($aa =~/[DNEQ]/gi)
	{
		++$acid_cnt;
	}
	if($aa=~/[KRH]/gi)
	{
	   	++$base_cnt;
	}
	
	say "$aa pos: ", pos($aa) // 'pos reset';
	
	if($aa=~/[DNEQKRH]/gi)
	{
	    ++$neutral_cnt;
	}
}