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

[EX Q]: Sentence: 'a blue fire hydrant painted on the bottom of it'. Find frequency of the letter 'h'
[EX A]: 2

[EX Q]: Sentence: 'a tennis player that is running to get the tennis ball'. Find frequency of the letter 't'
[EX A]: 7

[EX Q]: Sentence: 'a lot of broccoli sitting on a table'. Find frequency of the letter 'n'
[EX A]:
2