Good Pairs

A pair of integers $(a, b)$ is defined to be good, if $GCD(a, b) = x$ and $LCM(a, b) = y$, where $GCD(a, b)$ denotes the greatest common divisor of $a$ and $b$, and $LCM(a, b)$ denotes the least common multiple of $a$ and $b$. You are given two integers $x$ and $y$. You are to find the number of good pairs of integers $(a, b)$ such that $l ≤  a, b  ≤ r$. Note that pairs $(a, b)$ and $(b, a)$ ar