my $start = q{AA};
    my $next  = q{AB};
    my $count = 0;
    my $value;
    foreach my $entry ( @{$strings} ) {
        if ( $count == $#$strings ) {
            $next = q{$};
        }
        else {
            $next = q{\,\ } . _alpha_add($start);
        }
        $affiliation_string =~ m/$start\((.*?)\)($next)/s;
        $value                     = $1;
        $affiliation_key->{$entry} = $value;
        $start                     = _alpha_add($start);
        $next                      = _alpha_add($next);
        $count++;
    }