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

[EX Q]: Sentence: 'a large cooked pizza on a dining table'. Find frequency of the letter 'n'
[EX A]: 3

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

[EX Q]: Sentence: 'several people in a group are having a good time while two cakes are ready to be sliced'. Find frequency of the letter 'h'
[EX A]:
2