Z2nm-supermagic labeling of Cn#Cm

A Γ -supermagic labeling of a graph G = ( V , E ) with ∣ E ∣ = k is a bijection from E to an Abelian group Γ of order k such that the sum of labels of all incident edges of every vertex x ∈ V is equal to the same element μ ∈ Γ . We present a Z 2 n m -supermagic labeling of Cartesian product of two cycles, C n □ C m for n odd. This along with an earlier result by Ivančo proves that a Z 2 n m -supermagic labeling of C n □ C m exists for every n , m ≥ 3 .