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

[Q]: Sentence: 'two bigger elephants standing with a small elephant'. Find frequency of the letter 't'
[A]: 5

[Q]: Sentence: 'a woman throwing a frisbee on a field'. Find frequency of the letter 's'
[A]: 1

[Q]: Sentence: 'a woman with a racket goes to hit a tennis ball'. Find frequency of the letter 'a'
[A]:
6