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

[Q]: Sentence: 'a group of giraffes walk together by a hill'. Find frequency of the letter 'b'
[A]: 1


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


[Q]: Sentence: 'a family sits in the sand at the beachside'. Find frequency of the letter 'm'
[A]:
1