if ($_[1] == "1")
{push @{{$_[2]}{$_[0]}{$_[1]}}, $_[3];}

##</code><code>##

my ( $w, $x, $y, $z ) = @_;
if ( $x == 1 ) { # or $x eq "1"
  push @{{$y}{$w}{$x}}, $z;
}

##</code><code>##

@{$y->{$w}->{$x}}