instruction:
In this task, you need to count the number of times the given letter appears in the given sentence.
question:
Sentence: 'a plastic container next to a toilet on a wooden box'. Find frequency of the letter 'i'
answer:
3


question:
Sentence: 'a small white plane sitting on top of the ocean'. Find frequency of the letter 'e'
answer:
4


question:
Sentence: 'a man riding a surfboard on top of a flowing river'. Find frequency of the letter 'a'
answer:

5