In this task, you need to count the number of times the given letter appears in the given sentence.
--------
Question: Sentence: 'some giraffes moving across a big grass field'. Find frequency of the letter 'e'

Answer: 3


Question: Sentence: 'group of snowboarders on a snowy trail overlooking a mountain'. Find frequency of the letter 'r'

Answer: 5


Question: Sentence: 'this is an image of a woman playing tennis'. Find frequency of the letter 'f'

Answer:
1