> For the complete documentation index, see [llms.txt](https://trizen.gitbook.io/perl6-rosettacode/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://trizen.gitbook.io/perl6-rosettacode/programming_tasks/j/jewels_and_stones.md).

# Jewels and stones

```perl
sub count-jewels ( Str $j, Str $s --> Int ) {
    my %counts_of_all = $s.comb.Bag;
    my @jewel_list    = $j.comb.unique;

    return %counts_of_all ∩ @jewel_list.Bag ?? %counts_of_all{ @jewel_list }.sum !! 0;
}

say count-jewels 'aA' , 'aAAbbbb';
say count-jewels 'z'  , 'ZZ';
```

#### Output:

```
3
0
```