Sets And Relations

Let \(A=\{0,3,4,6,7,8,9,10\}\) and \(R\) be the relation defined on \(A\) such that \(R=\{(x, y) \in A \times A: x-y\) is odd positive integer or \(x-y=2\}\). The minimum number of elements that must be added to the relation \(R\), so that it is a symmetric relation, is equal to ____________.