// Luke Skywalker gave Chewbacca an integer number x. Chewbacca isn't good at numbers but he loves inverting digits in them. Inverting digit t means replacing it with digit 9 - t. // Help Chewbacca to ...

so the sum of the face up numbers equals target. You throw two dice, each with 5 faces. There is only one way to get a sum of 10: 5+5.