Let $f(m,n)$ denote the number of ways you can have toppings on the pizza with $m$ different toppings ($m ≥ 2$), using each topping on exactly $n$ slices ($n ≥ 1$). Reflections are considered distinct, rotations are not.
<img class="img-responsive center-block" alt="animation with 16 ways to have 3 different toppings on 2 slices each" src="https://cdn.freecodecamp.org/curriculum/project-euler/pizza-toppings.gif" style="background-color: white; padding: 10px;">
Find the sum of all $f(m,n)$ such that $f(m,n) ≤ {10}^{15}$.