∗ 0 1 2 3 0 0 0 0 0 1 0 1 2 3 2 0 2 0 2 3 0 3 2 1 {\displaystyle {\begin{array}{c||c|c|c|c|c|}*&0&1&2&3\\\hline 0&0&0&0&0\\1&0&1&2&3\\2&0&2&0&2\\3&0&3&2&1\\\end{array}}}