Consider two sets \( A \) and \( B \), each containing three numbers in A.P. Let the sum and the product of the elements of \( A \) be \( 36 \) and \( p \) respectively and the sum and the product of the elements of \( B \) be \( 36 \) and \( q \) respectively. Let \( d \) and \( D \) be the common differences of AP's in \( A \) and \( B \) respectively such that \( D = d + 3 \) and \( d > 0 \). If \( \dfrac{p+q}{p-q} = \dfrac{19}{5} \), then \( p - q \) is equal to
