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

my %iupac_dgn;
my @iupac_code=('M','R','W','S','Y','K','V','H','D','B','N');
my @iupac_den=('2','2','2','2','2','2','3','3','3','3','4');	 
       @iupac_dgn{@iupac_code}=@iupac_den;

       my $string = 'GGNMDNNSNNNNDBNVWVSMNNHYNBNG'; 
       my @residues = split(//, $string);
       my degeneracy = 1;

	foreach my $residues(@residues){
	   if(grep($_=~m/^$residues$/, keys %iupac_dgn)){
	           my $factor = $iupac_dgn{$residues};
		      $degeneracy = ($factor * $degeneracy);
			     }
	  } 

     printf PRIMER_PAIRS "%28s, %30d", $string, $degeneracy;