Let M be the matrix: $$ M = \begin{bmatrix} 2& 2& 0& 4\\ 0& 1& 3& 5\\ 2& 5& 3& 1\\ 3& 1& 7& 3\end{bmatrix} $$ And H be the sub group of $\mathbb {Z}^4$ created by the matrix' columns.
I need to display $\mathbb{Z}^4/H$ as a direct sum of cylic groups.
How can I do that ?
(I'm sorry but I don't know how to use the math formulas)