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

[Q]: Sentence: 'oranges are sitting in a bowl on a table'. Find frequency of the letter 'a'
[A]: 5


[Q]: Sentence: 'people playing wii bowling in a modern library'. Find frequency of the letter 'o'
[A]: 3


[Q]: Sentence: 'a woman touches a captive giraffe in a zoo enclosure'. Find frequency of the letter 'u'
[A]:
2