another help on input record separator clarity please

Please help me with this another misunderstanding of my perl.

My plan is to make input record separator to "\n\n" so that file records 
are separated by blank space.. and then
collect information and push them into array by joining.

But when I run this, it says uninitilized values...  I am doing 
something wrong.. aren't i


cat ././f_this.pl
#!/usr/bin/perl

use strict;
use warnings;

open "FH", "<", "/tmp/fgg", or die "cannot $!\n";

my @[EMAIL PROTECTED]
 $count;

while (<FH>) {
    local $/ = "\n\n";
    ++$count;

    my $fgh =~ /fgh\s+(\S+)/;
    my $ijk =~ /ijk\s+(\S+)/;
    my $lmk =~ /lmk\s+(\S+)/;
  
    push @[EMAIL PROTECTED]
 join('_', $fgh, $ijk, $lmk);
}

[root@[EMAIL PROTECTED]
 tmp]# cat fgg
abc
def
fgh 111
ijk 333
lmn 2

abc
def
fgh 222
ijk 121
lmk 23
[root@[EMAIL PROTECTED]
 tmp]#