instruction:
In this task, you need to count the number of times the given letter appears in the given sentence.
question:
Sentence: 'the receipts from a meal at a restaurant are for  a sandwich, chili, and apple'. Find frequency of the letter 'u'
answer:
1


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


question:
Sentence: 'a lone giraffe eating the bark off of a tree in a zoo enclosure'. Find frequency of the letter 'e'
answer:

8