#!/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;

##</code><code>##

$_ = 1 x shift;
while( /^(11+?)\1+$/ ) {
    print length $1; 
    $_= 1 x ( length() / length $1 ) 
}
print length;

##</code><code>##

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

my $x = shift;  # some number argument

for ( my $y = 2; $y <= $x; $y++ ) {
    next if $x % $y;
    $x /= $y;
    print $y, "\n";
    redo;
}

##</code><code>##

perl -le '$x=shift; for($y=2; $y<=$x; $y++) { next if $x%$y; $x/=$y; print $y; redo }' 7