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

Sentence: 'a surfer wipes out on a huge wave'. Find frequency of the letter 'a'
3

Sentence: 'a man in costume talking on a cell phone'. Find frequency of the letter 'm'
2

Sentence: 'two elephants facing each other touching trunks in an enclosure'. Find frequency of the letter 'f'

1