instruction:
In this task, you need to count the number of times the given letter appears in the given sentence.
question:
Sentence: 'a small boat travels on the water next to the shore'. Find frequency of the letter 'a'
answer:
5


question:
Sentence: 'an old woman is holding her cat in front of a camera'. Find frequency of the letter 'r'
answer:
3


question:
Sentence: 'a boy carrying a surfboard on a busy sidewalk'. Find frequency of the letter 'r'
answer:

4