@@How this problem works

@@ABELIAN

\ni We compute the canonical decomposition for the group
and then use the Kunneth formula, which gives the integral 
homology of a direct product of two groups in terms of tensor 
products of the integral homology of the factors.

\ni See also @General_abelian_groups@General_abelian_groups::General discussion@ for a general discussion of abelian groups. 