Non-zero elements of skew-symmetric matrices

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Let $A \in \mathfrak{so}(n,\mathbb{Z})$ be an integer-valued skew-symmetric matrix. Is there an equivalent matrix $A' \in \mathfrak{so}(n,\mathbb{Z})$, s.t. the number $m$ of non-zero entries is minimal (so $m$ is an invariant)? If so, is this minimal set of non-zero entries itself unique? How can they be determined?