#!/usr/bin/perl
use strict;
use warnings;

my $x = 7;  # Sample Input
my @a;
my @p;

for (my $i = 2; $i <= $x; $i++) {
    for (my $z = 2; $z <= $i; $z++) {
         push @p, $z unless $i % $z;
    }
    push @a, pop @p if $#p == 0;
    @p = ();
}
print $_, "\n" foreach @a;