8-Cycle Decompositions of the Cartesian Product of Two Complete Graphs

We establish necessary and sufficient conditions on \( m \) and \( n \) for \( K_m \times K_n \), the Cartesian product of two complete graphs, to be decomposable into cycles of length \( 8 \). We also provide a complete classification of the leaves that are possible with maximum packings of complete graphs with \( 8 \)-cycles.