Generate a Python program that has the following intention:

The intention of the program is to recursively iterate over the elements of the input list arr, and yield each element that is not a list.

The program uses a while loop to iterate over the elements of the input list arr. For each element, it checks if the element is not a list using the isinstance() function. If the element is not a list, it is yielded. If the element is a list, the function calls itself recursively on the list using the p1(x) syntax, and yields the elements of the inner list.

The program continues to iterate over the elements of the input list until the end of the list is reached. The output of the program is a generator that yields the elements of the input list that are not lists.