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


while (my $line = <DATA>)
{
  next if $line =~ /^\s*$/; #skip blank lines
  
  my ($label, @rest) = split ' ', $line;
  @rest = sort {$a <=> $b}@rest;  #numeric sort
  
  foreach my $col (@rest)
  {
     print "$label $col\n";
  }
}  

=prints
A 1
B 2
B 3
B 6
C 2
C 3
C 4
C 6
C 10
=cut



__DATA__
A 1

B 3 6 2

C 3 4 6 2 10