def split_words(txt):
    if " " in txt:
        return txt.split()
    elif "," in txt:
        return txt.replace(',',' ').split()
    else:
        return len([i for i in txt if i.islower() and ord(i)%2 == 0])
from typing import List
def mean_absolute_deviation(numbers: List[float]) -> float:
    mean = sum(numbers) / len(numbers)
    return sum(abs(x - mean) for x in numbers) / len(numbers)