#!/usr/bin/perl

use strict; # https://perlmonks.org/?node_id=11121442
use warnings;

my @data = qw( 5 );
my $target = 5;

my @answers = grep defined, map { $data[$_] == $target ? @data[$_ + 1 .. $_ + 3] : () } 0 .. $#data;
print "@answers\n";