instruction:
In this task, you need to count the number of times the given letter appears in the given sentence.
question:
Sentence: 'two giraffes, one standing and one laying down'. Find frequency of the letter 'g'
answer:
3


question:
Sentence: 'a passenger bus that is driving down the street'. Find frequency of the letter 'r'
answer:
3


question:
Sentence: 'a bear in a tree holding and chewing a branch'. Find frequency of the letter 'i'
answer:

3