I need help writing a function.

Write a function named filter that filters the elements of a dictionary by removing all key-value pairs that do not satisfy minimum criteria for keys and values.

The function filter takes three parameters:

1. d, a dictionary in which all keys are strings and all values are integers

2. kFilter, a string

3. vFilter, an integer

The function filter returns a dictionary containing all key-value pairs in d in which the key is less than kFilter and the value is less than vFilter.

For example, the following would be correct input and output:

>>> d = {'a': 1, 'b': 2, 'c': 3, 'd': 2, 'e': 1}

>>> filtered = filter(d, 'd', 3)

>>> print(filtered)

{'b': 2, 'a': 1}