instruction:
In this task, you need to count the number of times the given letter appears in the given sentence.
question:
Sentence: 'two bears swim in a blue pool of water'. Find frequency of the letter 'o'
answer:
4


question:
Sentence: 'apples, pears, and oranges are piled up for sale'. Find frequency of the letter 'a'
answer:
6


question:
Sentence: 'a pizza with cheese, olives, onions, and sauce'. Find frequency of the letter 'a'
answer:

4