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

[Q]: Sentence: 'a log in the water with three birds perched on it'. Find frequency of the letter 'r'
[A]: 4


[Q]: Sentence: 'a man pushing a cart full of bananas'. Find frequency of the letter 'u'
[A]: 2


[Q]: Sentence: 'a couple of zebras and antelopes captured on a wildlife camera'. Find frequency of the letter 'd'
[A]:
3