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

[EX Q]: Sentence: 'a plastic container next to a toilet on a wooden box'. Find frequency of the letter 'i'
[EX A]: 3

[EX Q]: Sentence: 'two elephants facing each other touching trunks in an enclosure'. Find frequency of the letter 'f'
[EX A]: 1

[EX Q]: Sentence: 'the wooden kitchen has a small child's plastic table in it'. Find frequency of the letter 'n'
[EX A]:
3