Create a function that takes in the sum and age difference of two people, calculates their individual ages, and returns a pair of values (oldest age first) if those exist or `null/None` if:
* `sum < 0`
* `difference < 0`
* Either of the calculated ages come out to be negative
def get_ages(add, dif):
    return None if any(n < 0 for n in (add, dif, add - dif)) else ((add + dif) / 2, (add - dif) / 2)

def get_ages(add, dif):
    return None if any(n < 0 for n in (add, dif, add - dif)) else ((add + dif) / 2, (add - dif) / 2)
