Given an array of integers, arr, of size n$,$ that represent the frequency of each element, for each element, do exactly one of these operations:

$1.$ Leave the frequency unchanged.

$2.$ Increase the frequency of the element by x$.$

$3.$ Decrease the frequency of the element by y$.$

$4.$ Multiply the frequency of the element by z$.$

Find the maximum number of elements with the same frequency that can be obtained.