Question

If \(a\), \(b\), and \(c\) are positive real numbers such that \(a > 10 \ge b \ge c\) and\[ \frac{\log_8(a+b)}{\log_2 c} + \frac{\log_{27}(a-b)}{\log_3 c} = \frac{2}{3} \]then the greatest possible integer value of \(a\) is