use warnings;
use strict;

is_prime( $ARGV[0] );

sub is_prime {
    my ($val) = @_;
    my $num_sqrt = int( sqrt($val) );
    my @factor;
    for ( 2 .. $num_sqrt ) {
        if ( ( $val % $_ ) == 0 ) {
            push @factor, $_;
        }
    }
    my $count = () = @factor;
    print $val, " is a Prime Number" if $count == 0;
}