#!/usr/bin/perl -w

use strict;

sub Mix;

my @Row1=(1,3,5,7);
my @Row2=(2,4,6);
my @Row3=(9,9,9);
my @Row4=Mix(\@Row1,\@Row2,\@Row3);

print "@Row4\n";

sub Mix
{
 my @Result;
 while(1)
 {
  my $Old=@Result;
  push @Result,grep $_,shift @{$_} for @_;
  last if @Result==$Old;
 };
 @Result;
};