use strict;
use warnings;
get_data();
get_data();

sub get_data    
{
   while ( <DATA> ) {
     print $_;
   }
}   ##get_data


__DATA__
A
B
C
D

##</code><code>##

while(1){
         last unless my $immed = pop @{$immed_child{$root}};
        get_descends($immed);
        $all_descends{$immed}++;
    }

##</code><code>##

    foreach my $immed ( @{$immed_child{$root}} )  {
        get_descends($immed);
        $all_descends{$immed}++;
    }