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

[EX Q]: Sentence: 'a picture of two computers on a table'. Find frequency of the letter 'r'
[EX A]: 2

[EX Q]: Sentence: 'a golden haired dog looking out of an open window'. Find frequency of the letter 'd'
[EX A]: 4

[EX Q]: Sentence: 'the person is skiing in the snowy area'. Find frequency of the letter 'h'
[EX A]:
2