#!perl

use 5.12.0;
use warnings;

my %h = ( 'a512_x64' => '24', 'world' => 'hello');

print $h{world}, "\n";   # line 5
print $h{a512_x64}, "\n"; # line 6

##</code><code>##

C:\_\tmp>num_underscore_problem.pl
hello
24