instruction:
In this task, you need to count the number of times the given letter appears in the given sentence.
question:
Sentence: 'a car accident has slowed traffic as a clean up crew works'. Find frequency of the letter 'f'
answer:
2


question:
Sentence: 'a plastic plastic plate topped with three different type of food'. Find frequency of the letter 'l'
answer:
3


question:
Sentence: 'fancy traffic light with arrows and a mirror'. Find frequency of the letter 'f'
answer:

3