In this task, you need to count the number of times the given letter appears in the given sentence.

Let me give you an example: Sentence: 'a large group of bananas proped up on several bicycles'. Find frequency of the letter 'e'
The answer to this example can be: 5
Here is why: The letter 'e' appears 5 times in the sentence.

OK. solve this:
Sentence: 'several generations of a family engaged in an entertainment activity'. Find frequency of the letter 'e'
Answer:
9