my SetHash $a = ('0/2', '2/2').SetHash; 
my @result = (); 
find-strongest($a); 
sub find-strongest(SetHash $a) { 
  my $keys = $a.keys; 
  for $keys.List -> $item { 
    my @split-item = $item.comb; 
    $a{$item}:delete; 
    find-strongest($a); 
  }
}