#arithmetic.pm
#!/usr/bin/perl -w
use strict;
package arithmetic;

sub gcd() {
   my ($a, $b) = @_;
  ($a,$b) = ($b,$a) if $a > $b;
  while ($a) {
    ($a, $b) = ($b % $a, $a);
  }
  return $b;
}

sub lcm {
    my ($a,$b)=@_;
    return $a*$b/&gcd($a,$b);
}

]