use strict;

my $max    = $ARGV[0] || 100;
my @primes = ( 2 );
for my $num ( 3 .. $max ) {
    my $sqrt = sqrt $num;
    for my $prime ( @primes ) {
        last unless $num % $prime;
        push @primes, $num and last if $prime > $sqrt;
    }
}

print join ", ", @primes;
print "\n";