sub r { my $s; $s .= chop for @_ = @_; $s . 0 ? ( &r , $s ) : () } #### sub recursive_s2a { my $str_last; foreach my $str (@_ = @_) { $str_last .= chop($str); } if ($str_last . 0) { return (recursive_s2a(@_) , $str_last ); } else { return; } }