</root>
XML

my $t= XML::Twig->new (twig_roots => {emp => \&emp, prod => \&prod});
my %emp;
my $currEmp;

$t->parse ($xml);

print "$_ - $emp{$_}\n" for sort keys %emp;


sub emp {
    my ($t, $data) = @_;
   
    $currEmp = $data->trimmed_text ();
    $emp{$currEmp} ||= '';
}


sub prod {
    my ($t, $data) = @_;
    my $text = $data->trimmed_text ();
    
    return if $text !~ /^\d+(\.\d*)?/;
    $emp{$currEmp} ||= 0;
    $emp{$currEmp} += $text;
}