instruction:
In this task, you need to count the number of times the given letter appears in the given sentence.
question:
Sentence: 'people playing wii bowling in a modern library'. Find frequency of the letter 'o'
answer:
3


question:
Sentence: 'a woman walking on a shore next to a river'. Find frequency of the letter 'v'
answer:
1


question:
Sentence: 'the gentleman is trying to fix his tie'. Find frequency of the letter 'm'
answer:

1