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

[Q]: Sentence: 'a man is taking a picture of a man and woman'. Find frequency of the letter 'a'
[A]: 8


[Q]: Sentence: 'a man riding on the back of a white horse next to other horses'. Find frequency of the letter 'o'
[A]: 6


[Q]: Sentence: 'a collection of folded dollar bills, multicolored ear plugs, toothbrushes, pills and spoons  neatly arranged in rows'. Find frequency of the letter 'u'
[A]:
3