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

[EX Q]: Sentence: 'a baby elephant walks beside an adult elephant along a post and cable'. Find frequency of the letter 'l'
[EX A]: 6

[EX Q]: Sentence: 'a small white dog looking out a car window'. Find frequency of the letter 'l'
[EX A]: 3

[EX Q]: Sentence: 'a dog that is standing near a hydrant'. Find frequency of the letter 'd'
[EX A]:
3