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

[Q]: Sentence: 'an area that has surrounded by a metal fence'. Find frequency of the letter 'o'
[A]: 1


[Q]: Sentence: 'a person with some scissors over a bowl'. Find frequency of the letter 's'
[A]: 6


[Q]: Sentence: 'there is an empty wooden bench at the park'. Find frequency of the letter 'h'
[A]:
3