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

Sentence: 'two giraffes standing next to some trees'. Find frequency of the letter 'f'
2

Sentence: 'many white birds flying above a river that flows in front of a forest'. Find frequency of the letter 'a'
5

Sentence: 'a large dog is laying on top of a woman on a couch'. Find frequency of the letter 'm'

1