sub sumit {
        my $sum = 0;
        map { $sum += $_ } split //, @_ ? $_[0] : $_;
        $sum
}

my @sums = map { sumit } map { sumit hex } split /\-/, '86C86720-42A0-1069-A2E8-08002B30309D';
print sprintf "%s\n", join '+', @sums;