#!/usr/bin/perl

use warnings;
use strict;

my @a = ('1', '2', '3', '4');
my @b = ('2', '3', '4', '5', '4', '3', '3', '6', '7');

my $x = 0;
while($b[$x] ne $a[$#a]) {
    $x++;
}

foreach my $i (@b[($x + 1) .. $#b]){
    print "$i\n";
}