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

my @names = ('rita', 'sue','bob', 'daisy');

while (@names){
  my $name1 = shift @names;
  my $name2 = shift @names;

 if( defined $name2){
    print "$name1 $name2\n";
    unshift @names, $name2;
   }else{ print "$name1\n";}
}