#!/usr/bin/perl

use strict;
use warnings;

my ($test, $count);

# WORKS
$test = <<'END';
ABCD
DEFG
END

$count = ($test =~ s/(BC?[DE])//gi);
print "Removed: <<$1>>\nCOUNT: $count\n";


# THIS ALSO WORKS
$test = <<'END';
ABCD
AEFG
END

$count = ($test =~ s/(BC?[DE])//gi);
print "Removed: <<$1>>\nCOUNT: $count\n";


# FAILS
$test = <<'END';
ABCD
ABFG
END

$count = ($test =~ s/(BC?[DE])//gi);
print "Removed: <<$1>>\nCOUNT: $count\n";