Show only the last four digits

A payment dashboard shows card numbers on receipts. To protect customers, every digit except the last four digits must be replaced by an asterisk *. Spaces, dashes and any other characters stay exactly where they are, so the card still looks like it was typed.

For example 4111-1111-1111-1234 becomes ****-****-****-1234. If the text contains four digits or fewer, nothing is hidden.

Task: read one line holding a card number written in any style (digits possibly separated by spaces or dashes). Print the masked version of that line. Only the digits are counted when deciding which four are the last four.